See also
anchors property
An array of objects corresponding to named anchors in source order. See anchor object.
appCodeName property
A string specifying the code name of the browser.
Syntax
navigator.appCodeName
Property of
Description
appCodeName is a read-only property.
Examples
The following example displays the value of the appCodeName property:
document.write("The value of navigator.appCodeName is " +
navigator.appCodeName)
For Navigator 2.0, this displays the following:
The value of navigator.appCodeName is Mozilla
See also
appName property
A string specifying the name of the browser.
Syntax
navigator.appName
Property of
Description
appName is a read-only property.
Examples
The following example displays the value of the appName property:
document.write("The value of navigator.appName is " +
navigator.appName)
For Navigator 2.0, this displays the following:
The value of navigator.appName is Netscape
See also
appVersion property
A string specifying version information for the Navigator.
Syntax
navigator.appVersion
Property of
Description
The appVersion property specifies version information in the following format:
releaseNumber (platform; country)
The values contained in this format are the following:
appVersion is a read-only property.
Examples
Example 1. The following example displays version information for the Navigator:
document.write("The value of navigator.appVersion is " +
navigator.appVersion)
For Navigator 2.0 on Windows 95, this displays the following:
The value of navigator.appVersion is 2.0 (Win95, I)
Example 2. The following example populates a textarea object with newline characters separating each line. Because the newline character varies from platform to platform, the example tests the appVersion property to determine whether the user is running Windows (appVersion contains "Win" for all versions of Windows). If the user is running Windows, the newline character is set to \r\n; otherwise, it's set to \n, which is the newline character for Unix and Macintosh.
See also
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.
Method of
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.
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
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.
Method of
Description
The atan method returns a numeric value between -pi/2 and pi/2 radians.
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
back method
Loads the previous URL in the history list.
Syntax
history.back()
Method of
Description
This method performs the same action as a user choosing the Back button in the Navigator. The back method is the same as history.go(-1).
Examples
The following custom buttons perform the same operations as the Navigator Back and Forward buttons:<P><INPUT TYPE="button" VALUE="< Back" onClick="history.back()"> <P><INPUT TYPE="button" VALUE="> Forward" onClick="history.forward()">
See also
bgColor property
A string specifying the color of the document background.
Syntax
document.bgColor
Property of
Description
The bgColor property is expressed as a hexadecimal RGB triplet or as one of the string literals listed in Color Values. This property is the JavaScript reflection of the BGCOLOR attribute of the <BODY> tag. The default value of this property is set by the user on the Colors tab of the Preferences dialog box, which is displayed by choosing General Preferences from the Options menu.
You can set the bgColor property at any time.
If you express the 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".
Examples
The following example sets the color of the document background to aqua using a string literal:
document.bgColor="aqua"
The following example sets the color of the document background to aqua using a hexadecimal triplet:
document.bgColor="00FFFF"
See also
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.
Method of
Description
Use the big method with the write or writeln methods to format and display a string in a document.
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:
See also
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.
Method of
Description
Use the blink method with the write or writeln methods to format and display a string in a document.
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:
See also
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.
Method of
password, select, text, textarea
Description
Use the blur method to remove focus from a specific form element.
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
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.
Method of
Description
Use the bold method with the write or writeln methods to format and display a string in a document.
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
button object
A pushbutton on an HTML form.
Syntax
To define a button:
<INPUT TYPE="button" NAME="buttonName" VALUE="buttonText" [onClick="handlerText"]>NAME="buttonName" specifies the name of the button object. You can access this value using the name property.
VALUE="buttonText" specifies the label to display on the button face. You can access this value using the value property.
To use a button object's properties and methods:
1. buttonName.propertyName 2. buttonName.methodName(parameters) 3. formName.elements[index].propertyName 4. formName.elements[index].methodName(parameters)buttonName is the value of the NAME attribute of a button object.
formName is either the value of the NAME attribute of a form object or an element in the forms array.
index is an integer representing a button object on a form.
propertyName is one of the properties listed below.
methodName is one of the methods listed below.
Property of
Description
A button object on a form looks as follows:
A button object is a form element and must be defined within a <FORM> tag.
The button object is a custom button that you can use to perform an action you define. The button executes the script specified by its onClick event handler.
Properties
Methods
Event handlers
Examples
The following example creates a button named calcButton. The text "Calculate" is displayed on the face of the button. When the button is clicked, the function calcFunction() is called.
See also
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
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
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.
Method of
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.
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
checkbox object
A checkbox on an HTML form. A checkbox is a toggle switch that lets the user set a value on or off.
Syntax
To define a checkbox, use standard HTML syntax with the addition of the onClick event handler:
<INPUT TYPE="checkbox" NAME="checkboxName" VALUE="checkboxValue" [CHECKED] [onClick="handlerText"]> textToDisplayNAME="checkboxName" specifies the name of the checkbox object. You can access this value using the name property.
VALUE="checkboxValue" specifies a value that is returned to the server when the checkbox is selected and the form is submitted. This defaults to "on". You can access this value using the value property.
CHECKED specifies that the checkbox is displayed as checked. You can access this value using the defaultChecked property.
textToDisplay specifies the label to display beside the checkbox.
To use a checkbox object's properties and methods:
1. checkboxName.propertyName 2. checkboxName.methodName(parameters) 3. formName.elements[index].propertyName 4. formName.elements[index].methodName(parameters)checkboxName is the value of the NAME attribute of a checkbox object.
formName is either the value of the NAME attribute of a form object or an element in the forms array.
index is an integer representing a checkbox object on a form.
propertyName is one of the properties listed below.
methodName is one of the methods listed below.
Property of
Description
A checkbox object on a form looks as follows:
A checkbox object is a form element and must be defined within a <FORM> tag.
Use the checked property to specify whether the checkbox is currently checked. Use the defaultChecked property to specify whether the checkbox is checked when the form is loaded.
Properties
Methods
Event handlers
Examples
Example 1. The following example displays a group of four checkboxes that all appear checked by default.
Example 2. The following example contains a form with three text boxes and one checkbox. The checkbox lets the user choose whether the text fields are converted to upper case. Each text field has an onChange event handler that converts the field value to upper case if the checkbox is checked. The checkbox has an onClick event handler that converts all fields to upper case when the user checks the checkbox.
See also
checked property
A Boolean value specifying the selection state of a checkbox object or radio button.
Syntax
1. checkboxName.checked 2. radioName[index].checked
checkboxName is either the value of the NAME attribute of a checkbox object or an element in the elements array.
radioName is the value of the NAME attribute of a radio object.
index is an integer representing a radio button in a radio object.
Property of
Description
If a checkbox or radio button is selected, the value of its checked property is true; otherwise, it is false.
You can set the checked property at any time. The display of the checkbox or radio button updates immediately when you set the checked property.
Examples
The following example examines an array of radio buttons called musicType on the musicForm form to determine which button is selected. The VALUE attribute of the selected button is assigned to the checkedButton variable.
function stateChecker() {
var checkedButton = ""
for (var i in document.musicForm.musicType) {
if (document.musicForm.musicType[i].checked=="1") {
checkedButton=document.musicForm.musicType[i].value
}
}
}
See also
clear method
Clears the document in a window.
Syntax
document.clear()
Method of
Description
The clear method empties the content of a window, regardless of how the content of the window has been painted.
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
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.
Method of
Description
See the description for the setTimeout method.
Examples
See the examples for the setTimeout method.
See also
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.
Method of
button, checkbox, radio, reset, submit
Description
The effect of the click method varies according to the calling element:
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()
Method of
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.
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
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.
Method of
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().
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
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.
Method of
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.
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
cookie property
String value of a cookie, which is a small piece of information stored by the Navigator in the cookies.txt file.
Syntax
document.cookie
Property of
Description
Use string methods such as substring, charAt, indexOf, and lastIndexOf to determine the value stored in the cookie. See the Netscape cookie specification for a complete specification of the cookie syntax.
You can set the cookie property at any time.
Examples
The following function uses the cookie property to record a reminder for users of an application. The "expires=" component sets an expiration date for the cookie, so it persists beyond the current browser session. The format of the date must be
Wdy, DD-Mon-YY HH:MM:SS GMTwhere Wdy is the full name of the day of the week, DD is an integer representation of the day of the month, Mon is the month, YY is the last two digits of the year, and HH, MM, and SS are two-digit representations of hours, minutes, and seconds, respectively.
This is the same date format as returned by Date.toGMTString, except:
- Dashes are added between the day, month, and year
- Year is two-digit for cookies.
For example, a valid cookie expiration date is:
expires=Wednesday, 09-Nov-99 23:12:40 GMT
function RecordReminder(time, expression) {
// Record a cookie of the form "@=" to map
// from in milliseconds since the epoch,
// returned by Date.getTime(), onto an encoded expression,
// (encoded to contain no white space, semicolon,
// or comma characters)
document.cookie = "@" + time + "=" + expression + ";"
// set the cookie expiration time to one day
// beyond the reminder time
document.cookie += "expires=" + cookieDate(time + 24*60*60*1000)
// cookieDate is a function that formats the date according to the cookie spec
}
When the user loads the page that contains this function, another function uses indexOf("@") and indexOf("=") to determine the date and time stored in the cookie.
See also
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.
Method of
Description
The cos method returns a numeric value between -1 and 1, which represents the cosine of the angle.
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
