JavaScript about new () inherit notes

Some recent study summary, if the error is not rigorous place, hope to point out!

Using the new operator has the following actions:

1. Create an Object temp = {} ,
2. temp.__proto__ = A.prototype ,
3. A.call(temp, arguments) ,
4. return temp .

    function A (name) {        this. Name= "a";    }      function B (name) {        this. Name= "b";    }    A.prototype.show=function() {        console.log ("showaaaaa");    }    B.prototype.show=function() {        console.log ("showbbbbb");    }

One: Using the A = new B () method

    a=New  B ();    Console.log (a);    Console.log (a.prototype);    Console.log (a.__proto__);    Console.log (A.constructor);
　  a.show ();    A.prototype.show ();    

Output:

function }//Use a = new B () when the original value of a is emptied, then assign the This property and the prototype property of B to a, and the value and function are bound to the properties of   a undefinedfunction  }//a = new B () way A has a hidden property __proto__ points to B.prototypefunction  B (name) {//with the first         this. Name= "B";    

Two: Using A.prototype = new B ()

    a.prototype=New  B ();    Console.log (a);    Console.log (a.prototype);    Console.log (a.__proto__);    Console.log (a.constructor);     // a.show ();     a.prototype.show ();    A.show ();

Output:

functionA (name) {//Use a.prototype=new B () when a property is not changed           This. Name= "A"; } b {Name:"B", Show:function}//But the prototype of a is completely covered by the This property and the prototype property of B, so the original prototype.show of  A is notfunctionEmpty () {}//a has no __proto__ attribute, A.prototype has __proto__ attribute pointing to B.prototype functionFunction () {[native code]} //Overrides A.prototype so A.constructor is empty and needs to be redefined once a's constructor points to SHOWBBBBB// Same as the second uncaught typeerror:undefined is not afunctionA does not show this function, A.prototype only

Three: a = new B () and a.prototype = new B () one

    a=New  B ();  ①    A.prototype=new  B ();  ②    Console.log (a);    Console.log (a.prototype);    Console.log (a.__proto__);
Console.log (a.prototype.__proto__);    Console.log (a.constructor);     A.prototype.show ();    A.show ();

Output:

function function function}//a and A.prototype all have a__proto__ Property
function}   function B (name) {        this. Name= "b";    } showbbbbb  //from ② showbbbbb  //from ① 

JavaScript about new () inherit notes