The Very Useful JavaScript call() And apply() Functions For Overriding 'this' For A Given Function.

apply

Syntax

functionreference.apply(thisArg, argArray)

Parameters

thisArg (parameter for the calling object)

argArray (an optional parameter of an argument array for the object)

Description

apply allows you to apply a method of another object in the context of a different object (the calling object). You can assign a different this object when calling an existing function. this refers to the current object, the calling object. With apply, you can write a method once and then inherit it in another object, without having to rewrite the method for the new object.

 

call

Syntax

functionreference.call(thisArg, arg1, arg2, ...)

Parameters

thisArg (parameter for the calling object)

arg1, arg2, ... (an optional parameters of arguments for the object)

Description

call allows you to call (executes) a method of another object in the context of a different object (the calling object). You can assign a different this object when calling an existing function. this refers to the current object, the calling object. With call, you can write a method once and then inherit it in another object, without having to rewrite the method for the new object.

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About metawrap

CTO Massive Interactive. Ex Computer Whiz Kid - Now Grumpy Old Guru.
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