René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"__proto__ 和 prototype","articleBody":"\u003cbr\u003e\n\n\u003e  Object includes a prototype linkage feature that allows one object to inherit the properties of another.\n\n基本上任何对象都有一个`__proto__`，并且都不为空，不能直接修改，而函数对象的prototype属性是可以修改的\n\n[ ES5中是`Object.getPrototypeOf()` ]\n\u003cbr\u003e\n\n``` javascript\nvar Person = function(name,age){\n      this.name = name || 'Down';\n      this.age = age || 18;\n}\n\nPerson.prototype.say = function(){\n      console.log(this.age);\n}\n\nvar person1 = new Person('John',10);\n\nperson1.__proto__;     //  Object {}    ==\u003e  Object.prototype\nconsole.log(person1.name, person1.age);    //  John 10\nperson1.say();    //  10\n\nvar person2 = new Person();\n\nperson2.say === person1.say;    //  true\n```\n\n\u003cbr\u003e\n\n``` javascript\nvar Person = {\n      name: 'Down' || this.name,\n      age: 18 || this.age\n}\n\nvar person1 = Object.create(Person);\n\nperson1.__proto__;       //    Object { name=\"Down\",  age=18}    ==\u003e  Person\nconsole.log(person1.name, person1.age);      //  Down  18\n\nperson1.age = 30;\nconsole.log(person1.name, person1.age);      //  Down  30\n\nvar person2 = Object.create(Person);\n\nperson1.name === person2.name;    //  true\n```\n\n`new fn()`，生成一个对象，对象的`__proto__`绑定到被调用的函数的`fn.prototype`上\n`Object.create(o)`创建的对象，生成的对象的`__proto__`绑定到`o`上\n\u003cbr\u003e\nJavaScript: The Good Parts,[ES5标准中已经可用]\n\n``` javascript\nObject.create = function (o) {\n      var F = function () {};\n      F.prototype = o;\n      return new F();\n};\n\nvar b=Object.create(a);\n```\n\n\u003cbr\u003e\n","author":{"url":"https://github.com/K0II","@type":"Person","name":"K0II"},"datePublished":"2016-05-23T08:42:56.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/2/JavaScript/issues/2"}