Javascript [Electronic resources] : The Definitive Guide (4th Edition) نسخه متنی

Availability

JavaScript 1.2; JScript 5.5;
ECMAScript v3

Synopsis

function.apply(thisobj, args)

Arguments

thisobj

The object to which function is to be
applied. In the body of the function,
thisobj becomes the value of the
this keyword.

args

An array of values to be passed as arguments to
function.

Returns

Whatever value is returned by the invocation of
function.

Throws

TypeError

If this method is invoked on an object that is not a function or if
this method is invoked with an args
argument that is not an array or an Arguments object.

Description

apply( ) invokes the specified
function as if it were a method of
thisobj, passing it the arguments
contained in the args array. It returns
the value returned by the function invocation. Within the body of the
function, the this keyword refers to the
thisobj object.

The args argument must be an array or an
Arguments object. Use Function.call( ) instead if
you want to specify the arguments to pass to the function
individually instead of as array elements.

Example

// Apply the default Object.toString(  ) method to an object that
// overrides it with its own version of the method. Note no arguments.
Object.prototype.toString.apply(o);
// Invoke the Math.max(  ) method with apply to find the largest
// element in an array. Note that first argument doesn't matter
// in this case.
var data = [1,2,3,4,5,6,7,8];
Math.max.apply(null, data);

See Also

Function.call( )