apply (Function.apply method)

public apply(thisObject:Object, [argArray:Array]) : Void

Specifies the value of thisObject 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.

Returns the value that the called function specifies as the return value.

Availability: ActionScript 1.0; Flash Player 6

Parameters

thisObject:Object - The object to which myFunction is applied.

argArray:Array [optional] - An array whose elements are passed to myFunction as parameters.

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() {
    trace("this == myObj? " + (this == myObj));
    trace("arguments: " + arguments);
}

// instantiate an object
var myObj:Object = new Object();

// create arrays to pass as a parameter to apply()
var firstArray:Array = new Array(1,2,3);
var secondArray:Array = new Array("a", "b", "c");

// use apply() to set the value of this to be myObj and send firstArray
theFunction.apply(myObj,firstArray);
// output: 
// this == myObj? true
// arguments: 1,2,3

// use apply() to set the value of this to be myObj and send secondArray
theFunction.apply(myObj,secondArray);
// output: 
// this == myObj? true
// arguments: a,b,c

apply (Function.apply method)

Parameters

Example

See also