關於 proto和prototype的一些理解

時間 2019-11-08

標籤關於 proto prototype 一些理解欄目微服務简体版

原文原文鏈接

var Person = function(name) {};prototype

Person.prototype.say = function() {
console.log("Person say");
}code

Person.prototype.age = 20;對象

var Man = function() {};
Man.prototype = new Person();
Man.prototype.physique = 'strong';blog

Man.prototype.age = 25;原型

var man = new Man();
man.say();
console.log(man.physique)
console.log(man.age);io

//實例的__proto__ 指向的對象原型prototype
console.log(man.__proto__ === Man.prototype);
console.log(man.constructor === Person);
console.log(man.__proto__.constructor === man.constructor);console

//對象的__proto__指向的都是Function的prototype
console.log(Person.constructor == Function);
console.log(Person.__proto__ == Function.prototype);
console.log(Person.__proto__.constructor == Function);
console.log(Person.prototype.constructor === Person);
console.log(Person.prototype.__proto__ === Object.prototype);function

console.log(Function.constructor === Function);
console.log(Function.prototype.constructor === Function);
console.log(Function.__proto__.constructor === Function);
//Function.__proto__ 、 Object.__protot__ 和Function.prototype 指代就是同一個對象funtion
console.log(Function.prototype===Function.__proto__);
console.log(Function.prototype===Object.__proto__);class

console.log(Object.prototype.__proto__=== null);
console.log(Object.__proto__.constructor == Function);di