ProcÚdures et Fonctions

Les procÚdure et fonctions suivantes sont disponibles dans JavaScript:

  • abs
  • acos
  • alert
  • anchor
  • asin
  • atan
  • back
  • big
  • blink
  • blur
  • bold
  • ceil
  • charAt
  • clear
  • clearTimeout
  • click
  • close (document)
  • close (window)
  • confirm
  • cos
  • escape
  • eval
  • exp
  • fixed
  • floor
  • focus
  • fontcolor
  • fontsize
  • forward
  • getDate
  • getDay
  • getHours
  • getMinutes
  • getMonth
  • getSeconds
  • getTime
  • getTimezoneOffset
  • getYear
  • go
  • indexOf
  • isNaN
  • italics
  • lastIndexOf
  • link
  • log
  • max
  • min
  • open (document)
  • open (window)
  • parse
  • parseFloat
  • parseInt
  • pow
  • prompt
  • random
  • round
  • select
  • setDate
  • setHours
  • setMinutes
  • setMonth
  • setSeconds
  • setTimeout
  • setTime
  • setYear
  • sin
  • small
  • sqrt
  • strike
  • sub
  • submit
  • substring
  • sup
  • tan
  • toGMTString
  • toLocaleString
  • toLowerCase
  • toUpperCase
  • unescape
  • UTC
  • write
  • writeln

  • ProcÚdure abs

    Retourne la valeur absolue d'un nombre.

    Syntaxe

    Math.abs(nombre)

    number is any numeric expression or a property of an existing object.

    Method of

    Math

    Examples

    In the following example, the user enters a number in the first text box and presses the Calculate button to display the absolute value of the number.

    <FORM>
    <P>Enter a number:
    <INPUT TYPE="text" NAME="absEntry">
    
    <P>The absolute value is:
    <INPUT TYPE="text" NAME="result">
    
    <P>
    <INPUT TYPE="button" VALUE="Calculate"
       onClick="form.result.value = Math.abs(form.absEntry.value)">
    
    </FORM>
    


    acos method

    Returns the arc cosine (in radians) of a number.

    Syntax

    Math.acos(number)

    number is a numeric expression between -1 and 1, or a property of an existing object.

    Description

    The acos method returns a numeric value between 0 and pi radians. If the value of number is outside the suggested range, the return value is always 0.

    Method of

    Math

    Examples

    // Displays the value 0
    document.write("The arc cosine of 1 is " + Math.acos(1))
    
    // Displays the value 3.141592653589793
    document.write("<P>The arc cosine of -1 is " + Math.acos(-1))
    
    // Displays the value 0
    document.write("<P>The arc cosine of 2 is " + Math.acos(2))
    

    See also

  • asin, atan, cos, sin, tan methods
  • alert method

    Displays an Alert dialog box with a message and an OK button.

    Syntax

    alert("message")

    message is any string or a property of an existing object.

    Description

    Use the alert method to display a message that does not require a user decision. The message argument specifies a message that the dialog box contains.

    Although alert is a method of the window object, you do not need to specify a windowReference when you call it. For example, windowReference.alert() is unnecessary.

    Method of

    window

    Examples

    In the following example, the testValue() function checks the name entered by a user in the text object of a form to make sure that it is no more than eight characters in length. This example uses the alert method to prompt the user to enter a valid value.

    function testValue(textElement) {
       if (textElement.length > 8) {
          alert("Please enter a name that is 8 characters or less")
       }
    }

    You can call the testValue() function in the onBlur event handler of a form's text object, as shown in the following example:

    Name: <INPUT TYPE="text" NAME="userName"
       onBlur="testValue(userName.value)">

    See also

  • confirm, prompt methods
  • anchor method

    Creates an HTML anchor that is used as a hypertext target.

    Syntax

    text.anchor(nameAttribute)

    text is any string or a property of an existing object.
    nameAttribute is any string or a property of an existing object.

    Description

    Use the anchor method with the write or writeln methods to programatically create and display an anchor in a document. Create the anchor with the anchor method, then call write or writeln to display the anchor in a document.

    In the syntax, the text string represents the literal text that you want the user to see. The nameAttribute string represents the NAME attribute of the <A> tag.

    Anchors created with the anchor method become elements in the anchors array. See the anchor object for information about the anchors array.

    Method of

    string

    Examples

    The following example opens the msgWindow window and creates an anchor for the Table of Contents:

       var myString="Table of Contents"
    
       msgWindow=window.open("","displayWindow")
       msgWindow.document.writeln(myString.anchor("contents_anchor"))
       msgWindow.document.close()
    
    

    The previous example produces the same output as the following HTML:

    <A NAME="contents_anchor">Table of Contents</A>
    
    
    

    See also

  • link method
  • asin method

    Returns the arc sine (in radians) of a number.

    Syntax

    Math.asin(number)

    number is a numeric expression between -1 and 1, or a property of an existing object.

    Description

    The asin method returns a numeric value between -pi/2 and pi/2 radians. If the value of number is outside the suggested range, the return value is always 0.

    Method of

    Math

    Examples

    // Displays the value 1.570796326794897 (pi/2)
    document.write("The arc sine of 1 is " + Math.asin(1))
    
    // Displays the value -1.570796326794897 (-pi/2)
    document.write("<P>The arc sine of -1 is " + Math.asin(-1))
    
    // Displays the value 0 because the argument is out of range
    document.write("<P>The arc sine of 2 is " + Math.asin(2))
    

    See also

  • acos, atan, cos, sin, tan methods
  • atan method

    Returns the arc tangent (in radians) of a number.

    Syntax

    Math.atan(number)

    number is either a numeric expression or a property of an existing object, representing the tangent of an angle.

    Description

    The atan method returns a numeric value between -pi/2 and pi/2 radians.

    Method of

    Math

    Examples

    // Displays the value 0.7853981633974483
    document.write("The arc tangent of 1 is " + Math.atan(1))
    
    // Displays the value -0.7853981633974483
    document.write("<P>The arc tangent of -1 is " + Math.atan(-1))
    
    // Displays the value 0.4636476090008061
    document.write("<P>The arc tangent of .5 is " + Math.atan(.5))
    

    See also

  • acos, asin, cos, sin, tan methods
  • back method

    Loads the previous URL in the history list.

    Syntax

    history.back()

    Description

    This method performs the same action as a user choosing the Back button in the Navigateur. The back method is the same as history.go(-1).

    Method of

    history

    Examples

    The following custom buttons perform the same operations as the Navigateur Back and Forward buttons:

    <P><INPUT TYPE="button" VALUE="< Back"
       onClick="history.back()">
    <P><INPUT TYPE="button" VALUE="> Forward"
       onClick="history.forward()">
    

    See also

  • forward, go methods
  • big method

    Causes a string to be displayed in a big font as if it were in a <BIG> tag.

    Syntax

    stringName.big()

    stringName is any string or a property of an existing object.

    Description

    Use the big method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses string methods to change the size of a string:

    var worldString="Hello, world"
    
    document.write(worldString.small())
    document.write("<P>" + worldString.big())
    document.write("<P>" + worldString.fontsize(7))
    

    The previous example produces the same output as the following HTML:

    <SMALL>Hello, world</SMALL>
    <P><BIG>Hello, world</BIG>
    <P><FONTSIZE=7>Hello, world</FONTSIZE>
    
    
    

    See also

  • fontsize, small methods
  • blink method

    Causes a string to blink as if it were in a <BLINK> tag.

    Syntax

    stringName.blink()

    stringName is any string or a property of an existing object.

    Description

    Use the blink method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses string methods to change the formatting of a string:

    var worldString="Hello, world"
    
    document.write(worldString.blink())
    document.write("<P>" + worldString.bold())
    document.write("<P>" + worldString.italics())
    document.write("<P>" + worldString.strike())
    

    The previous example produces the same output as the following HTML:

    <BLINK>Hello, world</BLINK>
    <P><B>Hello, world</B>
    <P><I>Hello, world</I>
    <P><STRIKE>Hello, world</STRIKE>
    
    
    

    See also

  • bold, italics, strike methods
  • blur method

    Removes focus from the specified object.

    Syntax

    1. passwordName.blur()
    2. selectName.blur()
    3. textName.blur()
    4. textareaName.blur()
    

    passwordName is either the value of the NAME attribute of a password object or an element in the elements array.
    selectName is either the value of the NAME attribute of a select object or an element in the elements array.
    textName is either the value of the NAME attribute of a text object or an element in the elements array.
    textareaName is either the value of the NAME attribute of a textarea object or an element in the elements array.

    Description

    Use the blur method to remove focus from a specific form element.

    Method of

    password, select, text, textarea

    Examples

    The following example removes focus from the password element userPass:

    userPass.blur()
    

    This example assumes that the password is defined as:

    <INPUT TYPE="password" NAME="userPass">

    See also

  • focus, select methods
  • bold method

    Causes a string to be displayed as bold as if it were in a <B> tag.

    Syntax

    stringName.bold()

    stringName is any string or a property of an existing object.

    Description

    Use the bold method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses string methods to change the formatting of a string:

    var worldString="Hello, world"
    
    document.write(worldString.blink())
    document.write("<P>" + worldString.bold())
    document.write("<P>" + worldString.italics())
    document.write("<P>" + worldString.strike())
    

    The previous example produces the same output as the following HTML:

    <BLINK>Hello, world</BLINK>
    <P><B>Hello, world</B>
    <P><I>Hello, world</I>
    <P><STRIKE>Hello, world</STRIKE>
    

    See also

  • blink, italics, strike methods
  • ceil method

    Returns the least integer greater than or equal to a number.

    Syntax

    Math.ceil(number)

    number is any numeric expression or a property of an existing object.

    Method of

    Math

    Examples

    //Displays the value 46
    document.write("The ceil of 45.95 is " + Math.ceil(45.95))
    
    //Displays the value -45
    document.write("<P>The ceil of -45.95 is " + Math.ceil(-45.95))
    

    See also

  • floor method
  • charAt method

    Returns the character at the specified index.

    Syntax

    stringName.charAt(index)

    stringName is any string or a property of an existing object.
    index is any integer from 0 to stringName.length - 1, or a property of an existing object.

    Description

    Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character is stringName.length - 1. If the index you supply is out of range, JavaScript returns an empty string.

    Method of

    string

    Examples

    The following example displays characters at different locations in the string "Brave new world".

    var anyString="Brave new world"
    
    document.write("The character at index 0 is " + anyString.charAt(0))
    document.write("The character at index 1 is " + anyString.charAt(1))
    document.write("The character at index 2 is " + anyString.charAt(2))
    document.write("The character at index 3 is " + anyString.charAt(3))
    document.write("The character at index 4 is " + anyString.charAt(4))
    

    See also

  • indexOf, lastIndexOf methods
  • clear method

    Clears the document in a window.

    Syntax

    document.clear()

    Description

    The clear method empties the content of a window, regardless of how the content of the window has been painted.

    Method of

    document

    Examples

    When the following function is called, the clear method empties the contents of the msgWindow window:

    function windowCleaner() {
       msgWindow.document.clear()
       msgWindow.document.close()
    }
    

    See also

  • close, open, write, writeln methods
  • clearTimeout method

    Cancels a timeout that was set with the setTimeout method.

    Syntax

    clearTimeout(timeoutID)

    timeoutID is a timeout setting that was returned by a previous call to the setTimeout method.

    Description

    See the description for the setTimeout method.

    Method of

    frame, window

    Examples

    See the examples for the setTimeout method.

    See also

  • setTimeout method
  • click method

    Simulates a mouse click on the calling form element.

    Syntax

    1. buttonName.click()
    2. radioName[index].click()
    
    3. checkboxName.click()
    

    buttonName is either the value of the NAME attribute of a button, reset, or submit object or an element in the elements array.
    radioName is the value of the NAME attribute of a radio object or an element in the elements array.
    index is an integer representing a radio button in a radio object.
    checkboxName is either the value of the NAME attribute of a checkbox object or an element in the elements array.

    Description

    The effect of the click method varies according to the calling element:

  • For button, reset, and submit, performs the same action as clicking the button.
  • For a radio, selects a radio button.
  • For a checkbox, checks the checkbox and sets its value to on.
  • Method of

    button, checkbox, radio, reset, submit

    Examples

    The following example toggles the selection status of the first radio button in the musicType radio object on the musicForm form:

    document.musicForm.musicType[0].click()

    The following example toggles the selection status of the newAge checkbox on the musicForm form:

    document.musicForm.newAge.click()


    close method (document object)

    Closes an output stream and forces data sent to layout to display.

    Syntax

    document.close()

    Description

    The close method closes a stream opened with the document.open() method. If the stream was opened to layout, the close method forces the content of the stream to display. Font style tags, such as <BIG> and <CENTER>, automatically flush a layout stream.

    The close method also stops the "meteor shower" in the Netscape icon and displays "Document: Done" in the status bar.

    Method of

    document

    Examples

    The following function calls document.close() to close a stream that was opened with document.open(). The document.close() method forces the content of the stream to display in the window.

    function windowWriter1() {
       var myString = "Hello, world!"
       msgWindow.document.open()
       msgWindow.document.write(myString + "<P>")
       msgWindow.document.close()
    }
    

    See also

  • clear, open, write, writeln methods
  • close method (window object)

    Closes the specified window.

    Syntax

    windowReference.close()

    windowReference is a valid way of referring to a window, as described in the window object.

    Description

    The close method closes the specified window. If you call close without specifying a windowReference, JavaScript closes the current window.

    In event handlers, you must specify window.close() instead of simply using close(). Due to the scoping of static objects in JavaScript, a call to close() without specifying an object name is equivalent to document.close().

    Method of

    window

    Examples

    Any of the following examples close the current window:

    window.close()
    self.close()
    close()

    The following example closes the messageWin window:

    messageWin.close()

    This example assumes that the window was opened in a manner similar to the following:

    messageWin=window.open("")

    See also

  • open method
  • confirm method

    Displays a Confirm dialog box with the specified message and OK and Cancel buttons.

    Syntax

    confirm("message")

    message is any string or a property of an existing object.

    Description

    Use the confirm method to ask the user to make a decision that requires either an OK or a Cancel. The message argument specifies a message that prompts the user for the decision. The confirm method returns true if the user chooses OK and false if the user chooses Cancel.

    Although confirm is a method of the window object, you do not need to specify a windowReference when you call it. For example, windowReference.confirm() is unnecessary.

    Method of

    window

    Examples

    This example uses the confirm method in the confirmCleanUp() function to confirm that the user of an application really wants to quit. If the user chooses OK, the custom cleanUp() function closes the application.

    function confirmCleanUp() {
       if (confirm("Are you sure you want to quit this application?")) {
          cleanUp()
       }
    }

    You can call the confirmCleanUp() function in the onClick event handler of a form's pushbutton, as shown in the following example:

    <INPUT TYPE="button" VALUE="Quit" onClick="confirmCleanUp()">

    See also

  • alert, prompt methods
  • cos method

    Returns the cosine of a number.

    Syntax

    Math.cos(number)

    number is a numeric expression representing the size of an angle in radians, or a property of an existing object.

    Description

    The cos method returns a numeric value between -1 and 1, which represents the cosine of the angle.

    Method of

    Math

    Examples

    //Displays the value 6.123031769111886e-017
    document.write("The cosine of PI/2 radians is " + Math.cos(Math.PI/2))
    
    //Displays the value -1
    document.write("<P>The cosine of PI radians is " + Math.cos(Math.PI))
    
    //Displays the value 1
    document.write("<P>The cosine of 0 radians is " + Math.cos(0))
    

    See also

  • acos, asin, atan, sin, tan methods
  • escape function

    Returns the ASCII encoding of an argument in the ISO Latin-1 character set.

    Syntax

    escape("string")

    string is a non-alphanumeric string in the ISO Latin-1 character set, or a property of an existing object.

    Description

    The escape function is not a method associated with any object, but is part of the language itself.

    The value returned by the escape function is a string of the form "%xx", where xx is the ASCII encoding of a character in the argument. If you pass the escape function an alphanumeric character, the escape function returns the same character.

    Examples

    The following example returns "%26"

    escape("&")
    

    The following example returns "%21%23"

    escape("!#")
    

    See also

  • unescape function
  • eval function

    The eval function evaluates a string and returns a value.

    Syntax

    eval(string)

    string is any string representing a JavaScript expression, statement, or sequence of statements. The expression can include variables and properties of existing objects.

    Description

    The eval function is a built-in JavaScript function. It is not a method associated with any object, but is part of the language itself.

    The argument of the eval function is a string. Do not call eval to evaluate an arithmetic expression. JavaScript evaluates arithmetic expressions automatically. If the argument represents an expression, eval evaluates the expression. If the argument represents one or more JavaScript statements, eval performs the statements.

    If you construct an arithmetic expression as a string, you can use eval to evaluate it at a later time. For example, suppose you have a variable x. You can postpone evaluation of an expression involving x by assigning the string value of the expression, say "3*x + 2", to a variable, and then calling eval at a later point in your script.

    Example

    Both of the write statements below display 42. The first evaluates the string "x + y + 1", and the second evaluates the string "42".

    var x = 2
    var y = 39
    var z = "42"
    document.write(eval("x + y + 1"), "
    " ) 
    document.write(eval(z), "
    " )
    

    In the following example, the getFieldName(n) function returns the name of the nth form element as a string. The first statement assigns the string value of the third form element to the variable field. The second statement uses eval to display the value of the form element.

    var field = getFieldName(3) 
    document.write("The field named ", field, " has value of ", eval(field + ".value"))
    

    The following example uses eval to evaluate the string str. This string consists of JavaScript statements that opens an alert dialog box and assigns z a value of 42 if x is five, and assigns zero to z otherwise. When the second statement is executed, eval will cause these statements to be performed, and it will also evaluate the set of statements and return the value that is assigned to z.

    var str = "if (x == 5) {alert('z is 42'); z = 42;} else z = 0; "
    document.write("

    z is ", eval(str))


    exp method

    Returns enumber, where number is the argument, and e is Euler's constant, the base of the natural logarithms.

    Syntax

    Math.exp(number)

    number is any numeric expression or a property of an existing object.

    Method of

    Math

    Examples

    //Displays the value 2.718281828459045
    document.write("The value of e<SUP>1</SUP> is " + Math.exp(1))
    

    See also

  • log, pow methods
  • fixed method

    Causes a string to be displayed in fixed-pitch font as if it were in a <TT> tag.

    Syntax

    stringName.fixed()

    stringName is any string or a property of an existing object.

    Description

    Use the fixed method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses the fixed method to change the formatting of a string:

    var worldString="Hello, world"
    
    document.write(worldString.fixed())
    

    The previous example produces the same output as the following HTML:

    <TT>Hello, world</TT>
    


    floor method

    Returns the greatest integer less than or equal to a number.

    Syntax

    Math.floor(number)

    number is any numeric expression or a property of an existing object.

    Method of

    Math

    Examples

    //Displays the value 45
    document.write("<P>The floor of 45.95 is " + Math.floor(45.95))
    
    //Displays the value -46
    document.write("<P>The floor of -45.95 is " + Math.floor(-45.95))
    

    See also

  • ceil method
  • focus method

    Gives focus to the specified object.

    Syntax

    1. passwordName.focus()
    2. selectName.focus()
    3. textName.focus()
    4. textareaName.focus()
    

    passwordName is either the value of the NAME attribute of a password object or an element in the elements array.
    selectName is either the value of the NAME attribute of a select object or an element in the elements array.
    textName is either the value of the NAME attribute of a text object or an element in the elements array.
    textareaName is either the value of the NAME attribute of a textarea object or an element in the elements array.

    Description

    Use the focus method to navigate to a specific form element and give it focus. You can then either programatically enter a value in the element or let the user enter a value.

    Method of

    password, select, text, textarea

    Examples

    In the following example, the checkPassword function confirms that a user has entered a valid password. If the password is not valid, the focus method returns focus to the password object and the select method highlights it so the user can re-enter the password.

    function checkPassword(userPass) {
       if (badPassword) {
          alert("Please enter your password again.")
          userPass.focus()
          userPass.select()
       }
    }

    This example assumes that the password is defined as:

    <INPUT TYPE="password" NAME="userPass">

    See also

  • blur, select methods
  • fontcolor method

    Causes a string to be displayed in the specified color as if it were in a <FONT COLOR=color> tag.

    Syntax

    stringName.fontcolor(color)

    stringName is any string or a property of an existing object.
    color is a string or a property of an existing object, expressing the color as a hexadecimal RGB triplet or as one of the string literals listed in Color Values.

    Description

    Use the fontcolor method with the write or writeln methods to format and display a string in a document.

    If you express color as a hexadecimal RGB triplet, you must use the format rrggbb. For example, the hexadecimal RGB values for salmon are red=FA, green=80, and blue=72, so the RGB triplet for salmon is "FA8072".

    The fontcolor method overrides a value set in the fgColor property.

    Method of

    string

    Examples

    The following example uses the fontcolor method to change the color of a string

    var worldString="Hello, world"
    
    document.write(worldString.fontcolor("maroon") +
       " is maroon in this line")
    document.write("<P>" + worldString.fontcolor("salmon") +
       " is salmon in this line")
    document.write("<P>" + worldString.fontcolor("red") +
       " is red in this line")
    
    document.write("<P>" + worldString.fontcolor("8000") +
       " is maroon in hexadecimal in this line")
    document.write("<P>" + worldString.fontcolor("FA8072") +
       " is salmon in hexadecimal in this line")
    document.write("<P>" + worldString.fontcolor("FF00") +
       " is red in hexadecimal in this line")
    

    The previous example produces the same output as the following HTML:

    <FONT COLOR="maroon">Hello, world</FONT> is maroon in this line
    <P><FONT COLOR="salmon">Hello, world</FONT> is salmon in this line
    <P><FONT COLOR="red">Hello, world</FONT> is red in this line
    
    <FONT COLOR="8000">Hello, world</FONT> is maroon in hexadecimal in this line
    <P><FONT COLOR="FA8072">Hello, world</FONT> is salmon in hexadecimal in this line
    <P><FONT COLOR="FF00">Hello, world</FONT> is red in hexadecimal in this line
    


    fontsize method

    Causes a string to be displayed in the specified font size as if it were in a <FONTSIZE=size> tag.

    Syntax

    stringName.fontsize(size)

    stringName is any string or a property of an existing object.
    size is an integer between one and seven, or a string representing a signed integer between 1 and 7, or a property of an existing object.

    Description

    Use the fontsize method with the write or writeln methods to format and display a string in a document. When you specify size as an integer, you set the size of stringName to one of the seven defined sizes. When you specify size as a string such as "-2", you adjust the font size of stringName relative to the size set in the <BASEFONT> tag.

    Method of

    string

    Examples

    The following example uses string methods to change the size of a string:

    var worldString="Hello, world"
    
    document.write(worldString.small())
    document.write("<P>" + worldString.big())
    document.write("<P>" + worldString.fontsize(7))
    

    The previous example produces the same output as the following HTML:

    <SMALL>Hello, world</SMALL>
    <P><BIG>Hello, world</BIG>
    <P><FONTSIZE=7>Hello, world</FONTSIZE>
    

    See also

  • big, small methods
  • forward method

    Loads the next URL in the history list.

    Syntax

    history.forward()

    Description

    This method performs the same action as a user choosing the Forward button in the Navigateur. The forward method is the same as history.go(1).

    Method of

    history

    Examples

    The following custom buttons perform the same operations as the Navigateur Back and Forward buttons:

    <P><INPUT TYPE="button" VALUE="< Back"
       onClick="history.back()">
    <P><INPUT TYPE="button" VALUE="> Forward"
       onClick="history.forward()">
    

    See also

  • back, go methods
  • getDate method

    Returns the day of the month for the specified date.

    Syntax

    dateObjectName.getDate()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getDate is an integer between 1 and 31.

    Method of

    Date

    Examples

    The second statement below assigns the value 25 to the variable day, based on the value of the date object Xmas95.

    Xmas95 = new Date("December 25, 1995 23:15:00")
    day = Xmas95.getDate()
    

    See also

  • setDate method
  • getDay method

    Returns the day of the week for the specified date.

    Syntax

    dateObjectName.getDay()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getDay is an integer corresponding to the day of the week: zero for Sunday, one for Monday, two for Tuesday, and so on.

    Method of

    Date

    Examples

    The second statement below assigns the value 1 to weekday, based on the value of the date object Xmas95. This is because December 25, 1995 is a Monday.

    Xmas95 = new Date("December 25, 1995 23:15:00")
    weekday = Xmas95.getDay()
    


    getHours method

    Returns the hour for the specified date.

    Syntax

    dateObjectName.getHours()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getHours is an integer between 0 and 23.

    Method of

    Date

    Examples

    The second statement below assigns the value 23 to the variable hours, based on the value of the date object Xmas95.

    Xmas95 = new Date("December 25, 1995 23:15:00")
    hours = Xmas95.getHours()
    

    See also

  • setHours method
  • getMinutes method

    Returns the minutes in the specified date.

    Syntax

    dateObjectName.getMinutes()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getMinutes is an integer between 0 and 59.

    Method of

    Date

    Examples

    The second statement below assigns the value 15 to the variable minutes, based on the value of the date object Xmas95.

    Xmas95 = new Date("December 25, 1995 23:15:00")
    minutes = Xmas95.getMinutes()
    

    See also

  • setMinutes method
  • getMonth method

    Returns the month in the specified date.

    Syntax

    dateObjectName.getMonth()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getMonth is an integer between zero and eleven. Zero corresponds to January, one to February, and so on.

    Method of

    Date

    Examples

    The second statement below assigns the value 11 to the variable month, based on the value of the date object Xmas95.

    Xmas95 = new Date("December 25, 1995 23:15:00")
    month = Xmas95.getDate()
    

    See also

  • setMonth method
  • getSeconds method

    Returns the seconds in the current time.

    Syntax

    dateObjectName.getSeconds()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getSeconds is an integer between 0 and 59.

    Method of

    Date

    Examples

    The second statement below assigns the value 30 to the variable secs, based on the value of the date object Xmas95.

    Xmas95 = new Date("December 25, 1995 23:15:30")
    secs = Xmas95.getSeconds()
    

    See also

  • setSeconds method
  • getTime method

    Returns the numeric value corresponding to the time for the specified date.

    Syntax

    dateObjectName.getTime()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by the getTime method is the number of milliseconds since 1 January 1970 00:00:00. You can use this method to help assign a date and time to another date object.

    Method of

    Date

    Examples

    The following example assigns the date value of theBigDay to sameAsBigDay.

    theBigDay = new Date("July 1, 1999")
    sameAsBigDay = new Date()
    sameAsBigDay.setTime(theBigDay.getTime())
    

    See also

  • setTime method
  • getTimezoneOffset method

    Returns the time zone offset in minutes for the current locale.

    Syntax

    dateObjectName.getTimezoneOffset()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The time zone offset is the difference between local time and GMT. Daylight savings time prevents this value from being a constant.

    Method of

    Date

    Examples

    x = new Date()
    currentTimeZoneOffsetInHours = x.getTimezoneOffset()/60
    


    getYear method

    Returns the year in the specified date.

    Syntax

    dateObjectName.getYear()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The value returned by getYear is the year less 1900. For example, if the year is 1976, the value returned is 76.

    Method of

    Date

    Examples

    The second statement below assigns the value 95 to the variable year, based on the value of the date object Xmas95.

    Xmas95 = new Date("December 25, 1995 23:15:00")
    year = Xmas95.getYear()
    

    See also

  • setYear method
  • go method

    Loads a URL from the history list.

    Syntax

    history.go(delta | "location")

    delta is an integer or a property of an existing object, representing a relative position in the history list.
    location is a string or a property of an existing object, representing all or part of a URL in the history list.

    Description

    The go method navigates to the location in the history list determined by the argument that you specify. You can interactively display the history list by choosing History from the Window menu. Up to 10 items in the history list are also displayed on the Go menu.

    The delta argument is a positive or negative integer. If delta is greater than zero, the go method loads the URL that is that number of entries forward in the history list; otherwise, it loads the URL that is that number of entries backward in the history list. If delta is 0, Navigateur reloads the current page.

    The location argument is a string. Use location to load the nearest history entry whose URL contains location as a substring. The location to URL matching is case-insensitive. Each section of a URL contains different information. See the location object for a description of the URL components.

    Method of

    history

    Examples

    The following button navigates to the nearest history entry that contains the string "home.netscape.com":

    <P><INPUT TYPE="button" VALUE="Go"
       onClick="history.go('home.netscape.com')">
    

    The following button navigates to the URL that is three entries backward in the history list:

    <P><INPUT TYPE="button" VALUE="Go"
       onClick="history.go(-3)">
    

    See also

  • back, forward methods
  • indexOf method

    Returns the index within the calling string object of the first occurrence of the specified value, starting the search at fromIndex.

    Syntax

    stringName.indexOf(searchValue, [fromIndex])

    stringName is any string or a property of an existing object.
    searchValue is a string or a property of an existing object, representing the value to search for.
    fromIndex is the location within the calling string to start the search from. It can be any integer from 0 to stringName.length - 1 or a property of an existing object.

    Description

    Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character is stringName.length - 1.

    If you do not specify a value for fromIndex, JavaScript assumes 0 by default. If searchValue is not found, JavaScript returns -1.

    Method of

    string

    Examples

    The following example uses indexOf and lastIndexOf to locate values in the string "Brave new world".

    var anyString="Brave new world"
    
    //Displays 8
    document.write("<P>The index of the first w from the beginning is " +
       anyString.indexOf("w"))
    //Displays 10
    document.write("<P>The index of the first w from the end is " +
       anyString.lastIndexOf("w"))
    //Displays 6
    document.write("<P>The index of 'new' from the beginning is " +
       anyString.indexOf("new"))
    //Displays 6
    document.write("<P>The index of 'new' from the end is " +
       anyString.lastIndexOf("new"))
    

    See also

  • charAt, lastIndexOf methods
  • isNaN function

    On Unix platforms, evaluates an argument to determine if it is "NaN" (not a number).

    Syntax

    isNaN(testValue)

    testValue is the value you want to evaluate.

    Description

    The isNaN function is a built-in JavaScript function. It is not a method associated with any object, but is part of the language itself. isNaN is available on Unix platforms only.

    On all platforms except Windows, the parseFloat and parseInt functions return "NaN" when they evaluate a value that is not a number. The "NaN" value is not a number in any radix. You can call the isNaN function to determine if the result of parseFloat or parseInt is "NaN". If "NaN" is passed on to arithmetic operations, the operation results will also be "NaN".

    The isNaN function returns true or false.

    Examples

    The following example evaluates floatValue to determine if it is a number, then calls a procedure accordingly.

    floatValue=parseFloat(toFloat)
    
    if isNaN(floatValue) {
       notFloat()
    } else {
       isFloat()
    }
    

    See also

  • parseFloat, parseInt functions
  • italics method

    Causes a string to be italicized as if it were in an <I> tag.

    Syntax

    stringName.italics()

    stringName is any string or a property of an existing object.

    Description

    Use the italics method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses string methods to change the formatting of a string:

    var worldString="Hello, world"
    
    document.write(worldString.blink())
    document.write("<P>" + worldString.bold())
    document.write("<P>" + worldString.italics())
    document.write("<P>" + worldString.strike())
    

    The previous example produces the same output as the following HTML:

    <BLINK>Hello, world</BLINK>
    <P><B>Hello, world</B>
    <P><I>Hello, world</I>
    <P><STRIKE>Hello, world</STRIKE>
    

    See also

  • blink, bold, strike methods
  • lastIndexOf method

    Returns the index within the calling string object of the last occurrence of the specified value. The calling string is searched backwards, starting at fromIndex.

    Syntax

    stringName.lastIndexOf(searchValue, [fromIndex])

    stringName is any string or a property of an existing object.
    searchValue is a string or a property of an existing object, representing the value to search for.
    fromIndex is the location within the calling string to start the search from. It can be any integer from 0 to stringName.length - 1 or a property of an existing object.

    Description

    Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character is stringName.length - 1.

    If you do not specify a value for fromIndex, JavaScript assumes stringName.length - 1 (the end of the string) by default. If searchValue is not found, JavaScript returns -1.

    Method of

    string

    Examples

    The following example uses indexOf and lastIndexOf to locate values in the string "Brave new world".

    var anyString="Brave new world"
    
    //Displays 8
    document.write("<P>The index of the first w from the beginning is " +
       anyString.indexOf("w"))
    //Displays 10
    document.write("<P>The index of the first w from the end is " +
       anyString.lastIndexOf("w"))
    //Displays 6
    document.write("<P>The index of 'new' from the beginning is " +
       anyString.indexOf("new"))
    //Displays 6
    document.write("<P>The index of 'new' from the end is " +
       anyString.lastIndexOf("new"))
    

    See also

  • charAt, indexOf methods
  • link method

    Creates an HTML hypertext link that jumps to another URL.

    Syntax

    linkText.link(hrefAttribute)

    linkText is any string or a property of an existing object.
    hrefAttribute is any string or a property of an existing object.

    Description

    Use the link method with the write or writeln methods to programatically create and display a hypertext link in a document. Create the link with the link method, then call write or writeln to display the link in a document.

    In the syntax, the linkText string represents the literal text that you want the user to see. The hrefAttribute string represents the HREF attribute of the <A> tag, and it should be a valid URL. Each section of a URL contains different information. See the location object for a description of the URL components.

    Links created with the link method become elements in the links array. See the link object for information about the links array.

    Method of

    string

    Examples

    The following example displays the word "Netscape" as a hypertext link that returns the user to the Netscape home page:

    var hotText="Netscape"
    var URL="http://www.netscape.com"
    
    document.open()
    document.write("Click to return to " + hotText.link(URL))
    document.close()
    

    The previous example produces the same output as the following HTML:

    Click to return to <A HREF="http://www.netscape.com">Netscape</A>

    See also

  • anchor method
  • log method

    Returns the natural logarithm (base e) of a number.

    Syntax

    Math.log(number)

    number is any positive numeric expression or a property of an existing object.

    Description

    If the value of number is outside the suggested range, the return value is always -1.797693134862316e+308.

    Method of

    Math

    Examples

    //Displays the value 2.302585092994046
    document.write("The natural log of 10 is " + Math.log(10))
    
    //Displays the value 0
    document.write("<P>The natural log of 1 is " + Math.log(1))
    
    //Displays the value -1.797693134862316e+308
    //because the argument is out of range
    document.write("<P>The natural log of 0 is " + Math.log(0))
    

    See also

  • exp, pow methods
  • max method

    Returns the greater of two numbers.

    Syntax

    max(number1, number2)

    number1 and number2 are any numeric arguments or the properties of existing objects.

    Method of

    Math

    Examples

    //Displays the value 20
    document.write("The maximum value is " + Math.max(10,20))
    
    //Displays the value -10
    document.write("<P>The maximum value is " + Math.max(-10,-20))
    

    See also

  • min method
  • min method

    Returns the lesser of two numbers.

    Syntax

    min(number1, number2)

    number1 and number2 are any numeric arguments or the properties of existing objects.

    Method of

    Math

    Examples

    //Displays the value 10
    document.write("

    The minimum value is " + Math.min(10,20)) //Displays the value -20 document.write("<P>The minimum value is " + Math.min(-10,-20))

    See also

  • max method
  • open method (document object)

    Opens a stream to collect the output of write or writeln methods.

    Syntax

    document.open(["mimeType"])

    mimeType specifies any of the following document types:

       text/html
       text/plain
       image/gif
       image/jpeg
       image/x-bitmap
       plugIn
    

    plugIn is any two-part plug-in MIME type that Netscape supports.

    Description

    The open method opens a stream to collect the output of write or writeln methods. If the mimeType is text or image, the stream is opened to layout; otherwise, the stream is opened to a plug-in. If a document exists in the target window, the open method clears it.

    End the stream by using the document.close() method. The close method causes text or images that were sent to layout to display. After using document.close(), issue document.open() again when you want to begin another output stream.

    mimeType is an optional argument that specifies the type of document to which you are writing. If you do not specify a mimeType, the open method assumes text/html by default.

    Following is a description of mimeType:

  • text/html specifies a document containing ASCII text with HTML formatting.
  • text/plain specifies a document containing plain ASCII text with end-of-line characters to delimit displayed lines.
  • image/gif specifies a document with encoded bytes constituting a GIF header and pixel data.
  • image/jpeg specifies a document with encoded bytes constituting a JPEG header and pixel data.
  • image/x-bitmap specifies a document with encoded bytes constituting a bitmap header and pixel data.
  • plugIn loads the specified plug-in and uses it as the destination for write and writeln methods. For example, "x-world/vrml" loads the VR Scout VRML plug-in from Chaco Communications, and "application/x-director" loads the Macromedia Shockwave plug-in.
  • Method of

    document

    Examples

    The following function calls document.open() to open a stream before issuing a write method:

    function windowWriter1() {
       var myString = "Hello, world!"
       msgWindow.document.open()
       msgWindow.document.write("<P>" + myString)
       msgWindow.document.close()
    }
    

    In the following example, the probePlugIn() function determines whether a user has the ShockWave plug-in installed:

    function probePlugIn(mimeType) {
       var havePlugIn = false
       var tiny = window.open("", "teensy", "width=1,height=1")
       if (tiny != null) {
          if (tiny.document.open(mimeType) != null)
             havePlugIn = true
          tiny.close()
       }
       return havePlugIn
    }
    
    var haveShockWavePlugIn = probePlugIn("application/x-director")
    

    See also

  • clear, close, write, writeln methods
  • open method (window object)

    Opens a new web browser window.

    Syntax

    [windowVar = ][window].open("URL", "windowName", ["windowFeatures"])
    

    windowVar is the name of a new window. Use this variable when referring to a window's properties, methods, and containership.
    URL specifies the URL to open in the new window. See the location object for a description of the URL components.
    windowName is the window name to use in the TARGET attribute of a <FORM> or <A> tag. windowName can contain only alphanumeric or underscore (_) characters.
    windowFeatures is a comma-separated list of any of the following options and values:

       toolbar[=yes|no]|[=1|0]
       location[=yes|no]|[=1|0]
       directories[=yes|no]|[=1|0]
       status[=yes|no]|[=1|0]
       menubar[=yes|no]|[=1|0]
       scrollbars[=yes|no]|[=1|0]
       resizable[=yes|no]|[=1|0]
       width=pixels
       height=pixels
    

    You may use any subset of these options. Separate options with a comma. Do not put spaces between the options.

    pixels is a positive integer specifying the dimension in pixels.

    Description

    The open method opens a new web browser window on the client, similar to choosing File|New Web Browser from the menu of the Navigateur. The URL argument specifies the URL contained by the new window. If URL is an empty string, a new, empty window is created.

    In event handlers, you must specify window.open() instead of simply using open(). Due to the scoping of static objects in JavaScript, a call to open() without specifying an object name is equivalent to document.open().

    windowFeatures is an optional, comma-separated list of options for the new window. The boolean windowFeatures options are set to true if they are specified without values, or as yes or 1. For example, open("", "messageWindow", "toolbar") and open("", "messageWindow", "toolbar=1") both set the toolbar option to true. If windowName does not specify an existing window and you do not specify windowFeatures, all boolean windowFeatures are true by default. If you specify any item in windowFeatures, all other Boolean windowFeatures are false unless you explicitly specify them.

    Following is a description of the windowFeatures:

  • toolbar creates the standard Navigateur toolbar, with buttons such as "Back" and "Forward", if true
  • location creates a Location entry field, if true
  • directories creates the standard Navigateur directory buttons, such as "What's New" and "What's Cool", if true
  • status creates the status bar at the bottom of the window, if true
  • menubar creates the menu at the top of the window, if true
  • scrollbars creates horizontal and vertical scrollbars when the document grows larger than the window dimensions, if true
  • resizable allows a user to resize the window, if true
  • width specifies the width of the window in pixels
  • height specifies the height of the window in pixels
  • Method of

    window

    Examples

    In the following example, the windowOpener function opens a window and uses write methods to display a message:

    function windowOpener() {
       msgWindow=window.open("","displayWindow","menubar=yes")
       msgWindow.document.write
          ("<HEAD><TITLE>Message window</TITLE></HEAD>")
       msgWindow.document.write
          ("<CENTER><BIG><B>Hello, world!</B></BIG></CENTER>")
    }
    

    The following is an onClick event handler that opens a new client window displaying the content specified in the file sesame.htm. The window opens with the specified option settings; all other options are false because they are not specified.

    <FORM NAME="myform">
    <INPUT TYPE="button" NAME="Button1" VALUE="Open Sesame!"
       onClick="window.open
       ('sesame.htm', 'newWin', 'scrollbars=yes,status=yes,width=300,height=300')">
    </FORM>
    
    

    Notice the use of single quotes (') inside the onClick event handler.

    See also

  • close method
  • parse method

    Returns the number of milliseconds in a date string since January 1, 1970 00:00:00, local time.

    Syntax

    Date.parse(dateString)

    dateString is a string representing a date or a property of an existing object.

    Description

    The parse method takes a date string (such as "Dec 25, 1995"), and returns the number of milliseconds since January 1, 1970 00:00:00 (local time). This function is useful for setting date values based on string values, for example in conjunction with the setTime method and the Date object.

    Given a string representing a time, parse returns the time value. It accepts the IETF standard date syntax: "Mon, 25 Dec 1995 13:30:00 GMT". It understands the continental US time zone abbreviations, but for general use, use a time zone offset, for example "Mon, 25 Dec 1995 13:30:00 GMT+0430" (4 hours, 30 minutes west of the Greenwich meridian). If you do not specify a time zone, the local time zone is assumed. GMT and UTC are considered equivalent.

    Because the parse function is a static method of Date, you always use it as Date.parse(), rather than as a method of a date object you created.

    Method of

    Date

    Examples

    If IPOdate is an existing date object, then

    IPOdate.setTime(Date.parse("Aug 9, 1995"))
    

    See also

  • UTC method
  • parseFloat function

    Parses a string argument and returns a floating point number.

    Syntax

    parseFloat(string)

    string is a string that represents the value you want to parse.

    Description

    The parseFloat function is a built-in JavaScript function. It is not a method associated with any object, but is part of the language itself.

    parseFloat parses its argument, a string, and returns a floating point number. If it encounters a character other than a sign ( + or -), numeral (0-9), a decimal point, or an exponent, then it returns the value up to that point and ignores that character and all succeeding characters.

    If the first character cannot be converted to a number, parseFloat returns one of the following values:

  • 0 on Windows platforms.
  • "NaN" on any other platform, indicating that the value is not a number.
  • For arithmetic purposes, the "NaN" value is not a number in any radix. You can call the isNaN function to determine if the result of parseFloat is "NaN". If "NaN" is passed on to arithmetic operations, the operation results will also be "NaN".

    Examples

    The following examples all return 3.14:

    parseFloat("3.14")
    parseFloat("314e-2")
    parseFloat("0.0314E+2")
    var x = "3.14"
    parseFloat(x)
    

    The following example returns "NaN" or 0:

    parseFloat("FF2")
    

    See also

  • isNaN, parseInt functions
  • parseInt function

    Parses a string argument and returns an integer of the specified radix or base.

    Syntax

    parseInt(string [,radix])

    string is a string that represents the value you want to parse.
    radix is an integer that represents the radix of the return value.

    Description

    The parseInt function is a built-in JavaScript function. It is not a method associated with any object, but is part of the language itself.

    The parseInt function parses its first argument, a string, and attempts to return an integer of the specified radix (base). For example, a radix of 10 indicates to convert to a decimal number, 8 octal, 16 hexadecimal, and so on. For radixes above 10, the letters of the alphabet indicate numerals greater than 9. For example, for hexadecimal numbers (base 16), A through F are used.

    If parseInt encounters a character that is not a numeral in the specified radix, it ignores it and all succeeding characters and returns the integer value parsed up to that point. ParseInt truncates numbers to integer values.

    If the radix is not specified or is specified as 0, JavaScript assumes the following:

  • If the input string begins with "0x", the radix is 16 (hexadecimal).
  • If the input string begins with "0", the radix is 8 (octal).
  • If the input string begins with any other value, the radix is 10 (decimal).
  • If the first character cannot be converted to a number, parseFloat returns one of the following values:

  • 0 on Windows platforms.
  • "NaN" on any other platform, indicating that the value is not a number.
  • For arithmetic purposes, the "NaN" value is not a number in any radix. You can call the isNaN function to determine if the result of parseInt is "NaN". If "NaN" is passed on to arithmetic operations, the operation results will also be "NaN".

    Examples

    The following examples all return 15:

    parseInt("F", 16)
    parseInt("17", 8)
    parseInt("15", 10)
    parseInt(15.99, 10)
    parseInt("FXX123", 16)
    parseInt("1111", 2)
    parseInt("15*3", 10)
    

    The following examples all return "NaN" or 0:

    parseInt("Hello", 8)
    parseInt("0x7", 10)
    parseInt("FFF", 10)
    

    Even though the radix is specified differently, the following examples all return 17 because the input string begins with "0x".

    parseInt("0x11", 16)
    parseInt("0x11", 0)
    parseInt("0x11")
    

    See also

  • isNaN, parseFloat functions
  • pow method

    Returns base to the exponent power, that is, baseexponent.

    Syntax

    pow(base, exponent)

    base is any numeric expression or a property of an existing object.
    exponent is any numeric expression or a property of an existing object.

    Method of

    Math

    Examples

    //Displays the value 49
    document.write("7 to the power of 2 is " + Math.pow(7,2))
    
    //Displays the value 1024
    document.write("<P>2 to the power of 10 is " + Math.pow(2,10))
    

    See also

  • exp, log methods
  • prompt method

    Displays a Prompt dialog box with a message and an input field.

    Syntax

    prompt(message, [inputDefault])

    message is any string or a property of an existing object; the string is displayed as the message.
    inputDefault is a string, integer, or property of an existing object that represents the default value of the input field.

    Description

    Use the prompt method to display a dialog box that receives user input. If you do not specify an initial value for inputDefault, the dialog box displays the value <undefined>.

    Although prompt is a method of the window object, you do not need to specify a windowReference when you call it. For example, windowReference.prompt() is unnecessary.

    Method of

    window

    Examples

    prompt("Enter the number of cookies you want to order:", 12)
    

    See also

  • alert, confirm methods
  • random method

    Returns a pseudo-random number between zero and one. This method is available on Unix platforms only.

    Syntax

    Math.random()

    Method of

    Math

    Examples

    //Displays a random number between 0 and 1
    document.write("The random number is " + Math.random())
    


    round method

    Returns the value of a number rounded to the nearest integer.

    Syntax

    round(number)

    number is any numeric expression or a property of an existing object.

    Description

    If the fractional portion of number is .5 or greater, the argument is rounded to the next highest integer. If the fractional portion of number is less than .5, the argument is rounded to the next lowest integer.

    Method of

    Math

    Examples

    //Displays the value 20
    document.write("The rounded value is " + Math.round(20.49))
    
    //Displays the value 21
    document.write("<P>The rounded value is " + Math.round(20.5))
    
    //Displays the value -20
    document.write("<P>The rounded value is " + Math.round(-20.5))
    
    //Displays the value -21
    document.write("<P>The rounded value is " + Math.round(-20.51))
    


    select method

    Selects the input area of the specified password, text, or textarea object.

    Syntax

    1. passwordName.select()
    2. textName.select()
    3. textareaName.select()
    

    passwordName is either the value of the NAME attribute of a password object or an element in the elements array.
    textName is either the value of the NAME attribute of a text object or an element in the elements array.
    textareaName is either the value of the NAME attribute of a textarea object or an element in the elements array.

    Description

    Use the select method to highlight the input area of a form element. You can use the select method with the focus method to highlight a field and position the cursor for a user response.

    Method of

    password, text, textarea

    Examples

    In the following example, the checkPassword function confirms that a user has entered a valid password. If the password is not valid, the select method highlights the password field and the focus method returns focus to it so the user can re-enter the password.

    function checkPassword(userPass) {
       if (badPassword) {
          alert("Please enter your password again.")
          userPass.focus()
          userPass.select()
       }
    }

    This example assumes that the password is defined as:

    <INPUT TYPE="password" NAME="userPass">

    See also

  • blur, focus methods
  • setDate method

    Sets the day of the month for a specified date.

    Syntax

    dateObjectName.setDate(dayValue)

    dateObjectName is either the name of a date object or a property of an existing object.
    dayValue is an integer from 1 to 31 or a property of an existing object, representing the day of the month.

    Method of

    Date

    Examples

    The second statement below changes the day for theBigDay to the 24th of July from its original value.

    theBigDay = new Date("July 27, 1962 23:30:00")
    theBigDay.setDate(24)
    

    See also

  • getDate method
  • setHours method

    Sets the hours for a specified date.

    Syntax

    dateObjectName.setHours(hoursValue)

    dateObjectName is either the name of a date object or a property of an existing object.
    hoursValue is an integer between 0 and 23 or a property of an existing object, representing the hour.

    Method of

    Date

    Examples

    theBigDay.setHours(7)
    

    See also

  • getHours method
  • setMinutes method

    Sets the minutes for a specified date.

    Syntax

    dateObjectName.setMinutes(minutesValue)

    dateObjectName is either the name of a date object or a property of an existing object.
    minutesValue is an integer between 0 and 59 or a property of an existing object, representing the minutes.

    Method of

    Date

    Examples

    theBigDay.setMinutes(45)
    

    See also

  • getMinutes method
  • setMonth method

    Sets the month for a specified date.

    Syntax

    dateObjectName.setMonth(monthValue)

    dateObjectName is either the name of a date object or a property of an existing object.
    monthValue is an integer between 0 and 11 (representing the months January through Decemeber), or a property of an existing object.

    Method of

    Date

    Examples

    theBigDay.setMonth(6)
    

    See also

  • getMonth method
  • setSeconds method

    Sets the seconds for a specified date.

    Syntax

    dateObjectName.setSeconds(secondsValue)

    dateObjectName is either the name of a date object or a property of an existing object.
    secondsValue is an integer between 0 and 59 or a property of an existing object.

    Method of

    Date

    Examples

    theBigDay.setSeconds(30)
    

    See also

  • getSeconds method
  • setTime method

    Sets the value of a date object.

    Syntax

    dateObjectName.setTime(timevalue) 

    dateObjectName is either the name of a date object or a property of an existing object.
    timevalue is an integer or a property of an existing object, representing the number of milliseconds since the epoch (1 January 1970 00:00:00).

    Description

    Use the setTime method to help assign a date and time to another date object.

    Method of

    Date

    Examples

    theBigDay = new Date("July 1, 1999")
    sameAsBigDay = new Date()
    sameAsBigDay.setTime(theBigDay.getTime())
    

    See also

  • getTime method
  • setTimeout method

    Evaluates an expression after a specified number of milliseconds have elapsed.

    Syntax

    timeoutID=setTimeout(expression, msec)

    timeoutID is an identifier that is used only to cancel the evaluation with the clearTimeout method.
    expression is a string expression or a property of an existing object.
    msec is a numeric value, numeric string, or a property of an existing object in millisecond units.

    Description

    The setTimeout method evaluates an expression after a specified amount of time. It does not evaluate the expression repeatedly. For example, if a setTimeout method specifies 5 seconds, the expression is evaluated after 5 seconds, not every 5 seconds.

    Method of

    frame, window

    Examples

    Example 1. The following example displays an alert message 5 seconds (5,000 milliseconds) after the user clicks a button. If the user clicks the second button before the alert message is displayed, the timeout is cancelled and the alert does not display.

    <SCRIPT LANGUAGE="JavaScript">
    function displayAlert() {
       alert("5 seconds have elapsed since the button was clicked.")
    }
    </SCRIPT>
    <BODY>
    <FORM>
    Click the button on the left for a reminder in 5 seconds; 
    click the button on the right to cancel the reminder before 
    it is displayed.
    <P>
    <INPUT TYPE="button" VALUE="5-second reminder"
       NAME="remind_button"
       onClick="timerID=setTimeout('displayAlert()',5000)">
    <INPUT TYPE="button" VALUE="Clear the 5-second reminder"
       NAME="remind_disable_button"
       onClick="clearTimeout(timerID)">
    </FORM>
    </BODY>
    
    
    

    Example 2. The following example displays the current time in a text object. The showtime() function, which is called recursively, uses the setTimeout method update the time every second.

    <HEAD>
    <SCRIPT LANGUAGE="JavaScript">
    <!--
    var timerID = null
    var timerRunning = false
    function stopclock(){
        if(timerRunning)
            clearTimeout(timerID)
        timerRunning = false
    }
    function startclock(){
         // Make sure the clock is stopped
        stopclock()
        showtime()
    }
    function showtime(){
        var now = new Date()
        var hours = now.getHours()
        var minutes = now.getMinutes()
        var seconds = now.getSeconds()
        var timeValue = "" + ((hours > 12) ? hours - 12 : hours)
        timeValue  += ((minutes < 10) ? ":0" : ":") + minutes
        timeValue  += ((seconds < 10) ? ":0" : ":") + seconds
        timeValue  += (hours >= 12) ? " P.M." : " A.M."
        document.clock.face.value = timeValue 
        timerID = setTimeout("showtime()",1000)
        timerRunning = true
    }
    //-->
    </SCRIPT>
    </HEAD>
    
    <BODY onLoad="startclock()">
    <FORM NAME="clock" onSubmit="0">
        <INPUT TYPE="text" NAME="face" SIZE=12 VALUE ="">
    </FORM>
    </BODY>
    
    
    
    

    See also

  • clearTimeout method
  • setYear method

    Sets the year for a specified date.

    Syntax

    dateObjectName.setYear(yearValue)

    dateObjectName is either the name of a date object or a property of an existing object.
    yearValue is an integer greater than 1900 or a property of an existing object.

    Method of

    Date

    Examples

    theBigDay.setYear(96)
    

    See also

  • getYear method
  • sin method

    Returns the sine of a number.

    Syntax

    Math.sin(number)

    number is a numeric expression or a property of an existing object, representing the size of an angle in radians.

    Description

    The sin method returns a numeric value between -1 and 1, which represents the sine of the angle.

    Method of

    Math

    Examples

    //Displays the value 1
    document.write("The sine of pi/2 radians is " +
       Math.sin(Math.PI/2))
    
    //Displays the value 1.224606353822377e-016
    document.write("<P>The sine of pi radians is " +
       Math.sin(Math.PI))
    
    //Displays the value 0
    document.write("<P>The sine of 0 radians is " +
       Math.sin(0))
    

    See also

  • acos, asin, atan, cos, tan methods
  • small method

    Causes a string to be displayed in a small font as if it were in a <SMALL> tag.

    Syntax

    stringName.small()

    stringName is any string or a property of an existing object.

    Description

    Use the small method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses string methods to change the size of a string:

    var worldString="Hello, world"
    
    document.write(worldString.small())
    document.write("<P>" + worldString.big())
    document.write("<P>" + worldString.fontsize(7))
    

    The previous example produces the same output as the following HTML:

    <SMALL>Hello, world</SMALL>
    <P><BIG>Hello, world</BIG>
    <P><FONTSIZE=7>Hello, world</FONTSIZE>
    

    See also

  • big, fontsize methods
  • sqrt method

    Returns the square root of a number.

    Syntax

    Math.sqrt(number)

    number is any non-negative numeric expression or a property of an existing object.

    Description

    If the value of number is outside the suggested range, the return value is always 0.

    Method of

    Math

    Examples

    //Displays the value 3
    document.write("The square root of 9 is " + Math.sqrt(9))
    
    //Displays the value 1.414213562373095
    document.write("<P>The square root of 2 is " + Math.sqrt(2))
    
    //Displays the value 0 because the argument is out of range
    document.write("<P>The square root of -1 is " + Math.sqrt(-1))
    


    strike method

    Causes a string to be displayed as struck out text as if it were in a <STRIKE> tag.

    Syntax

    stringName.strike()

    stringName is any string or a property of an existing object.

    Description

    Use the strike method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses string methods to change the formatting of a string:

    var worldString="Hello, world"
    
    document.write(worldString.blink())
    document.write("<P>" + worldString.bold())
    document.write("<P>" + worldString.italics())
    document.write("<P>" + worldString.strike())
    

    The previous example produces the same output as the following HTML:

    <BLINK>Hello, world</BLINK>
    <P><B>Hello, world</B>
    <P><I>Hello, world</I>
    <P><STRIKE>Hello, world</STRIKE>
    

    See also

  • blink, bold, italics methods
  • sub method

    Causes a string to be displayed as a subscript as if it were in a <SUB> tag.

    Syntax

    stringName.sub()

    stringName is any string or a property of an existing object.

    Description

    Use the sub method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses the sub and sup methods to format a string:

    var superText="superscript"
    var subText="subscript"
    
    document.write("This is what a " + superText.sup() + " looks like.")
    document.write("<P>This is what a " + subText.sub() + " looks like.")
    

    The previous example produces the same output as the following HTML:

    This is what a <SUP>superscript</SUP> looks like.
    <P>This is what a <SUB>subscript</SUB> looks like.
    

    See also

    sup method


    submit method

    Submits a form.

    Syntax

    formName.submit()

    formName is the name of any form or an element in the forms array.

    Description

    The submit method submits the specified form. It performs the same action as a submit button.

    Use the submit method to send data back to an http server. The submit method returns the data using either "get" or "post", as specified in the method property.

    Method of

    form

    Examples

    The following example submits a form called musicChoice:

    document.musicChoice.submit()
    

    If musicChoice is the first form created, you also can submit it as follows:

    document.forms[0].submit()
    

    See also the example for the form object.

    See also

  • submit object
  • onSubmit event handler
  • substring method

    Returns a subset of a string object.

    Syntax

    stringName.substring(indexA, indexB)

    stringName is any string or a property of an existing object.
    indexA is any integer from 0 to stringName.length - 1, or a property of an existing object.
    indexB is any integer from 0 to stringName.length - 1, or a property of an existing object.

    Description

    Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character is stringName.length - 1.

    If indexA is less than indexB, the substring method returns the subset starting with the character at indexA and ending with the character before indexB. If indexA is greater than indexB, the substring method returns the subset starting with the character at indexB and ending with the character before indexA. If indexA is equal to indexB, the substring method returns the empty string.

    Method of

    string

    Examples

    The following example uses substring to display characters from the string "Netscape".

    var anyString="Netscape"
    
    //Displays "Net"
    document.write(anyString.substring(0,3))
    document.write(anyString.substring(3,0))
    //Displays "cap"
    document.write(anyString.substring(4,7))
    document.write(anyString.substring(7,4))
    


    sup method

    Causes a string to be displayed as a superscript as if it were in a <SUP> tag.

    Syntax

    stringName.sup()

    stringName is any string or a property of an existing object.

    Description

    Use the sup method with the write or writeln methods to format and display a string in a document.

    Method of

    string

    Examples

    The following example uses the sub and sup methods to format a string:

    var superText="superscript"
    var subText="subscript"
    
    document.write("This is what a " + superText.sup() + " looks like.")
    document.write("<P>This is what a " + subText.sub() + " looks like.")
    

    The previous example produces the same output as the following HTML:

    This is what a <SUP>superscript</SUP> looks like.
    <P>This is what a <SUB>subscript</SUB> looks like.
    

    See also

  • sub method
  • tan method

    Returns the tangent of a number.

    Syntax

    Math.tan(number)

    number is a numeric expression representing the size of an angle in radians, or a property of an existing object.

    Description

    The tan method returns a numeric value which represents the tangent of the angle.

    Method of

    Math

    Examples

    //Displays the value 0.9999999999999999
    document.write("The tangent of pi/4 radians is " +
       Math.tan(Math.PI/4))
    
    //Displays the value 0
    document.write("<P>The tangent of 0 radians is " +
       Math.tan(0))
    

    See also

  • acos, asin, atan, cos, sin methods
  • toGMTString method

    Converts a date to a string, using the Internet GMT conventions.

    Syntax

    dateObjectName.toGMTString()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    The exact format of the value returned by toGMTString varies according to the platform.

    Method of

    Date

    Examples

    In the following example, today is a date object:

    today.toGMTString()
    

    In this example, the toGMTString method converts the date to GMT (UTC) using the operating system's time zone offset and returns a string value that is similar to the following form. The exact format depends on the platform.

    Mon, 18 Dec 1995 17:28:35 GMT

    See also

  • toLocaleString method
  • toLocaleString method

    Converts a date to a string, using the current locale's conventions.

    Syntax

    dateObjectName.toLocaleString()

    dateObjectName is either the name of a date object or a property of an existing object.

    Description

    If you are trying to pass a date using toLocaleString, be aware that different locales assemble the string in different ways. Using methods such as getHours, getMinutes, and getSeconds will give more portable results.

    Method of

    Date

    Examples

    In the following example, today is a date object:

    today.toLocaleString()
    

    In this example, toLocaleString returns a string value that is similar to the following form. The exact format depends on the platform.

    12/18/95 17:28:35

    See also

  • toGMTString method
  • toLowerCase method

    Returns the calling string value converted to lower case.

    Syntax

    stringName.toLowerCase()

    stringName is any string or a property of an existing object.

    Description

    The toLowerCase method returns the value of stringName converted to lower case. toLowerCase does not affect the value of stringName itself.

    Method of

    string

    Examples

    The following examples both yield "alphabet".

    var upperText="ALPHABET"
    document.write(upperText.toLowerCase())
    
    "ALPHABET".toLowerCase()
    

    See also

  • toUpperCase method
  • toUpperCase method

    Returns the calling string value converted to upper case.

    Syntax

    stringName.toUpperCase()

    stringName is any string or a property of an existing object.

    Description

    The toUpperCase method returns the value of stringName converted to upper case. toUpperCase does not affect the value of stringName itself.

    Method of

    string

    Examples

    The following examples both yield "ALPHABET".

    var lowerText="alphabet"
    document.write(lowerText.toUpperCase())
    
    "alphabet".toUpperCase()
    

    See also

  • toLowerCase method
  • unescape function

    Returns the ASCII string for the specified value.

    Syntax

    unescape("string")

    string is a string or a property of an existing object, containing characters in either of the following forms:

  • "%integer", where integer is a number between 0 and 255 (decimal)
  • "hex", where hex is a number between 0x0 and 0xFF (hexadecimal)
  • Description

    The unescape function is not a method associated with any object, but is part of the language itself.

    The string returned by the unescape function is a series of characters in the ISO Latin-1 character set.

    Examples

    The following example returns "&"

    unescape("%26")
    

    The following example returns "!#"

    unescape("%21%23")
    

    See also

  • escape function
  • UTC method

    Returns the number of milliseconds in a date object since January 1, 1970 00:00:00, Universal Coordinated Time (GMT).

    Syntax

    Date.UTC(year, month, day [, hrs] [, min] [, sec])

    year is a year after 1900.
    month is a month between 0-11.
    date is a day of the month between 1-31.
    hrs is hours between 0-23.
    min is minutes between 0-59.
    sec is seconds between 0-59.

    Description

    UTC takes comma-delimited date parameters and returns the number of milliseconds since January 1, 1970 00:00:00, Universal Coordinated Time (GMT).

    Because UTC is a static method of Date, you always use it as Date.UTC(), rather than as a method of a date object you created.

    Method of

    Date

    Examples

    The following statement creates a date object using GMT instead of local time:

    gmtDate = new Date(Date.UTC(96, 11, 1, 0, 0, 0))
    

    See also

  • parse method
  • write method

    Writes one or more HTML expressions to a document in the specified window.

    Syntax

    write(expression1 [,expression2], ...[,expressionN])

    expression1 through expressionN are any JavaScript expressions or the properties of existing objects.

    Description

    The write method displays any number of expressions in a document window. You can specify any JavaScript expression with the write method, including numerics, strings, or logicals.

    The write method is the same as the writeln method, except the write method does not append a newline character to the end of the output.

    Use the write method within any <SCRIPT> tag or within an event handler. Event handlers execute after the original document closes, so the write method will implicitly open a new document of mimeType text/html if you do not explicitly issue a document.open() method in the event handler.

    Method of

    document

    Examples

    In the following example, the write method takes several arguments, including strings, a numeric, and a variable:

    var mystery = "world"
    // Displays Hello world testing 123
    msgWindow.document.write("Hello ", mystery, " testing ", 123)
    

    In the following example, the write method takes two arguments. The first argument is an assignment expression, and the second argument is a string literal.

    //Displays Hello world...
    msgWindow.document.write(mystr = "Hello "+ "world...")
    

    In the following example, the write method takes a single argument that is a conditional expression. If the value of the variable age is less than 18, the method displays "Minor". If the value of age is greater than or equal to 18, the method displays "Adult".

    msgWindow.document.write(status = (age >= 18) ? "Adult" : "Minor")
    

    See also

  • close, clear, open, writeln methods
  • writeln method

    Writes one or more HTML expressions to a document in the specified window and follows them with a newline character.

    Syntax

    writeln(expression1 [,expression2], ...[,expressionN])

    expression1 through expressionN are any JavaScript expressions or the properties of existing objects.

    Description

    The writeln method displays any number of expressions in a document window. You can specify any JavaScript expression, including numerics, strings, or logicals.

    The writeln method is the same as the write method, except the writeln method appends a newline character to the end of the output. HTML ignores the newline character, except within certain tags such as <PRE>.

    Use the writeln method within any <SCRIPT> tag or within an event handler. Event handlers execute after the original document closes, so the writeln method will implicitly open a new document of mimeType text/html if you do not explicitly issue a document.open() method in the event handler.

    Method of

    document

    Examples

    All the examples used for the write method are also valid with the writeln method.

    See also

  • close, clear, open, write methods