MACROMEDIA FLASH MX, Reference

Page: 311 / 1104

Function.apply() 311
Function.apply()
Availability
Flash Player 6.
Usage
myFunction .apply( thisObject:Object , argumentsArray:Array )
Parameters
thisObject
The object to which
myFunction
is applied.
argumentsArray
An array whose elements are passed to
myFunction
as parameters.
Returns
Any value that the called function specifies.
Description
Method; specifies the value of
this
to be used within any function that ActionScript calls. This
method also specifies the parameters to be passed to any called function. Because
apply()
is a
method of the Function class, it is also a method of every Function object in ActionScript.
The parameters are specified as an Array object, unlike Function.call() , which specifies parameters
as a comma-delimited list. This is often useful when the number of parameters to be passed is not
known until the script actually executes.
Example
The following function invocations are equivalent:
Math.atan2(1, 0)
Math.atan2.apply(null, [1, 0])
The following simple example shows how
apply()
passes an array of parameters:
function theFunction() {
trace(arguments);
}
// create a new array to pass as a parameter to apply()
var firstArray:Array = new Array(1,2,3);
theFunction.apply(null,firstArray);
// outputs: 1,2,3
// create a second array to pass as a parameter to apply()
var secondArray:Array = new Array("a", "b", "c");
theFunction.apply(null,secondArray);
// outputs a,b,c
The following example shows how
apply()
passes an array of parameters and specifies the value
of
this
:
// define a function
function theFunction() {