js 原型

   1:  function Person (name,age) {

   2:              this.name = name;

   3:              this.age = age;

   4:          }

   5:   

   6:          Person.prototype = {

   7:              constructor : Person, // 原型{}这种格式得重新定义指向 要不然默认是Object

   8:              getInfo: function() {

   9:                  return 'A ' + this.name + ' ' + this.age + '.';

  10:              }

  11:          };

  12:   

  13:          var p = new Person('Lily',18);

  14:   

  15:          /**

  16:           * Person的prototype属性指向Person的prototype对象

  17:           * Person的实例p的__proto__属性指向Preson的prototype对象

  18:           * Preson的prototype对象的constructor属性指向Person

  19:           */

  20:          console.log(p.constructor); // Person

  21:          console.log(p.__proto__ == Person.prototype); // true

  22:          console.log(p.__proto__.constructor == Person); // true  p.__proto__ 指向Person的prototype对象 Person的prototype对象constructor属性指向Person构造器

  23:   

  24:          //Object.create EcmaScript5 以上有

  25:          var Person2 = Object.create(p); //复制对象

  26:          console.log(Person2.name);// Lily

  27:          Person2.age = 20;

  28:          console.log(Person2.age);// 20

  29:          console.log(p.age);// 20

  30:   

  31:          var o1 = Object.create({x:1, y:2});

  32:          var o2 = Object.create(Object.prototype);

  33:          console.log(o2);

  34:          console.log(new Object());

function Person (name,age) {
            this.name = name;
            this.age = age;
        }

        Person.prototype = {
            constructor : Person, // 原型{}这种格式得重新定义指向 要不然默认是Object
            getInfo: function() {
                return 'A ' + this.name + ' ' + this.age + '.';
            }
        };

        var p = new Person('Lily',18);

        /**
         * Person的prototype属性指向Person的prototype对象
         * Person的实例p的__proto__属性指向Preson的prototype对象
         * Preson的prototype对象的constructor属性指向Person
         */
        console.log(p.constructor); // Person
        console.log(p.__proto__ == Person.prototype); // true
        console.log(p.__proto__.constructor == Person); // true  p.__proto__ 指向Person的prototype对象 Person的prototype对象constructor属性指向Person构造器

        //Object.create EcmaScript5 以上有
        var Person2 = Object.create(p); //复制对象
        console.log(Person2.name);// Lily
        Person2.age = 20;
        console.log(Person2.age);// 20
        console.log(p.age);// 20

        var o1 = Object.create({x:1, y:2});
        var o2 = Object.create(Object.prototype);
        console.log(o2);
        console.log(new Object());