prototype和__proto__

//据说能理解这三行的,js原型已经攻克了 ? !!!

function Fun(){}

var a = new Fun();

console.log("0:\t",a.__proto__ == Fun.constructor.prototype.__proto__); //false

// 如何 解释/理解 上面的三行代码 ?

//so

//由 a.__proto__ == Fun.prototype

console.log("11:\t", a.__proto__ == Fun.prototype);

//得1 a.__proto__.__proto__ == Fun.prototype.__proto__ == Object.prototype

console.log("12:\t", a.__proto__.__proto__ == Fun.prototype.__proto__,Fun.prototype.__proto__ == Object.prototype);

//由 Fun.constructor.prototype == Fun.__proto__ == Function.prototype

console.log("21:\t", Fun.constructor.prototype == Fun.__proto__, Fun.__proto__ == Function.prototype );

//得2 Fun.constructor.prototype.__proto__ == Fun.__proto__.__proto__ == Function.prototype.__proto__ == Object.prototype

console.log("22:\t",

Fun.constructor.prototype.__proto__ == Fun.__proto__.__proto__,

Fun.__proto__.__proto__ == Function.prototype.__proto__,

Function.prototype.__proto__ == Object.prototype

);

//由1,2

//得3 a.__proto__.__proto__ == Fun.constructor.prototype.__proto__

console.log("31:\t",a.__proto__.__proto__ == Fun.constructor.prototype.__proto__);

//so a.__proto__ != a.__proto__.__proto__

console.log("32:\t",a.__proto__ != a.__proto__.__proto__);

//so Fun.prototype != Object.prototype

console.log("33:\t",Fun.prototype != Object.prototype);

//because Fun.prototype.__proto__ == Object.prototype

console.log("34:\t",Fun.prototype.__proto__ == Object.prototype);

//附 prototype和__proto__关系图

// http://note.youdao.com/noteshare?id=94f8bc1e9503902bd83d02f2a6706bec&sub=1EDCC088D57B4DBD891473B3F88D2D03

// http://note.youdao.com/noteshare?id=29af08eef11853ea53590d8d54f9a633&sub=EFB303175C134715A582CB1923492944