A brief talk on JavaScript overlay prototype and change prototype _javascript skill

Source: Internet
Author: User

Overwrite prototype

Prisoner example//1. Defines the prototype object var proto = {Sentence:4,//imprisonment years Probation:2//probation years}; 
 2. Define the constructor of the prototype object var prisoner = function (name, id) {this.name = name; 
This.id = ID; 
3. Associating the constructor with the prototype Prisoner.prototype = Proto; 4. Instantiate object--using factory function to instantiate object var Makeprisoner = function (name, ID) {//Use factory function to strength object prisoner var prisoner = object.create (pr 
 Prisoner.name = name; 
 Prisoner.id = ID; 
return prisoner; 
var firstprisoner = Makeprisoner (' Joe ', ' 12A '); Firstprisoner.sentence cannot find the sentence property in the Firstprisoner object,//So look up the prototype of the object and find both of these output 4 Console.log ( 
Console.log (firstprisoner.__proto__.sentence); 
Set the object's sentence property to ten firstprisoner.sentence = 10; 
Outputs 10//determines that the property value on the object has been set to Console.log (Firstprisoner.sentence); 
But the object's prototype did not change, and the value was still 4 console.log (firstprisoner.__proto__.sentence); 
Removes the delete firstprisoner.sentence from the object in order to get the property back to the value of the prototype; Next, the JavaScript engine cannot find the attribute on the object,//Must go back and look up the prototype chain and find the attribute on the prototype object//Both of thePut 4 console.log (firstprisoner.sentence); Console.log (firstprisoner.__proto__.sentence);

Ubuntu Terminal node output

xxh@xxh-e440:~/workspace$ node T6 

So what happens if you change the property value of a prototype object? I know you're thinking.

This article on the JavaScript cover prototype and change the prototype is small to share all the content of everyone, hope to give you a reference, but also hope that we support the cloud habitat community.

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