prototype和proto的区别

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vara = {};

console.log(a.prototype);  //undefinedconsole.log(a.__proto__);//Object {}varb =function(){}

console.log(b.prototype);  //b {}console.log(b.__proto__);//function() {}

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/*1、字面量方式*/

var a = {};

console.log(a.__proto__);  //Object {}

console.log(a.__proto__ === a.constructor.prototype); //true

/*2、构造器方式*/

var A = function(){};

var a = new A();

console.log(a.__proto__); //A {}

console.log(a.__proto__ === a.constructor.prototype); //true

/*3、Object.create()方式*/

var a1 = {a:1}

var a2 = Object.create(a1);

console.log(a2.__proto__); //Object {a: 1}

console.log(a.__proto__ === a.constructor.prototype); //false（此处即为图1中的例外情况）

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varA =function(){};vara =new A();

console.log(a.__proto__); //A {}（即构造器function A 的原型对象）console.log(a.__proto__.__proto__);//Object {}（即构造器function Object 的原型对象）console.log(a.__proto__.__proto__.__proto__);//null