javaScript uses call and apply

This time I will bring you javaScriptUsing call and apply, what are the precautions for using call and apply in javaScript, the following is a practical case, let's take a look.

call method:

Syntax: call(thisObj,Object)

Definition: Call a method of a object, Replaces the current object with another object.

Description:

The call method can be used to call a method instead of another object. The call method changes the object context of a function from the initial context to the new object specified by thisObj.
If the thisObj parameter is not provided, the Global object is used as thisObj.

apply method:

Syntax: apply(thisObj, [argArray])

Definition: Apply a method of a certain object and replace the current object with another object.

Note:

If argArray is not a valid array or is not an arguments object, a TypeError will be caused.

If neither argArray nor thisObj is provided, the Global object will be used as thisObj and no parameters can be passed.

eg1:

var pet={    words:'...',    speak:function(say){        console.log(say+' '+this.words)
    }
}var dog={    words:'Wang'}
pet.speak.call(dog,'speak')  //speak Wang

eg2

function Pet(word){    this.word=word;    this.speak=function(){        console.log(this.word)
    }
}function Dog(word){
    Pet.call(this,word)    //Pet.apply(this,arguments);  二者选其一即可}var dog=new Dog('Wang');
dog.speak();  //Wang

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to the php Chinese websiteOthersRelated article!

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Detailed explanation of javaScript objects

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