function SuperType(){
 this.property = true;
}
SuperType.prototype.getSuperValue = function(){
 return this.property;
};
function SubType(){
 this.subproperty = false;
}
//继承了SuperType
SubType.prototype = new SuperType();
SubType.prototype.getSubValue = function(){
 return this.subproperty;
}
var instance = new SubType();
alert(instance.getSuperValue());//true

function SuperType(){
 this.property = true;
}
SuperType.prototype.getSuperValue = function(){
 return this.property;
};
function SubType(){
 this.subproperty = false;
}
//继承了SuperType
SubType.prototype = new SuperType();

//添加了新方法
SubType.prototype.getSubValue = function(){
 return this.subproperty;
}
//重写超类型的方法
SubType.prototype.getSuperValue = function(){
 return false;
}
var instance = new SubType();
alert(instance.getSuperValue());//false

function SuperType(){
 this.property = true;
}
SuperType.prototype.getSuperValue = function(){
 return this.property;
};
function SubType(){
 this.subproperty = false;
}
//继承了SuperType
SubType.prototype = new SuperType();

//使用字面量方法添加新方法会导致上一行代码无效
SubType.prototype = {
 getSubValue : function(){
  return this,subproperty;
 },
 someOtherMethod : function(){
  return false;
 }
};
var instance = new SubType();
alert(instance.getSuperValue());//error

function SuperType(){
 this.colors = ['red','blue','green'];
}
function SubType(){}
//继承了SuperType
SubType.prototype = new SuperType();
var instance1 = new SubType();
instance1.colors.push('black');
alert(instance1.colors);//'red,blue,green,black'
var instance2 = new SubType();
alert(instance2.colors);//'red,blue,green,black'

function SuperType(){
 this.colors = ['red','blue','green'];
}
function SubType(){
 //继承了SuperType
 SuperType.call(this);
}
var instance1 = new SubType();
instance1.colors.push('black');
alert(instance1.colors);//'red,blue,green,black'
var instance2 = new SubType();
alert(instance2.colors);//'red,blue,green'

function SuperType(name){
 this.name = name;
}
function SubType(){
 //继承了SUperType,同时还传递了参数
 SuperType.call(this,"Nicholas");
 //实例属性
 this.age = 29;
}
var instance = new SubType();
alert(instance.name);//"Nicholas"
alert(instance.age);//29 

function SuperType(name){
 this.name = name;
 this.age = 30;
}
function SubType(){
 //实例属性
 this.age = 29;
 //继承了SUperType,同时还传递了参数
 SuperType.call(this,"Nicholas");
}
var instance = new SubType();
//实例属性被重写为SuperType构造函数的属性
alert(instance.age);//30

function SuperType(name){
 this.name = name;
 this.colors = ['red','blue','green'];
}
SuperType.prototype.sayName = function(){
 alert(this.name);
};
function SubType(name,age){
 //继承属性
 SuperType.call(this,name);
 this.age = age;
}
//继承方法
SubType.prototype = new SuperType();
SubType.prototype.constructor = SubType;
SubType.prototype.sayAge = function(){
 alert(this.age);
}
var instance1 = new SubType("Nicholas",29);
instance1.colors.push("black");
alert(instance1.colors);//'red,blue,green,black'
instance1.sayName();//"Nicholas"
instance1.sayAge();//29
var instance2 = new SubType("Greg",27);
alert(instance2.colors);//'red,blue,green'
instance2.sayName();//"Greg"
instance2.sayAge();//27

function SuperType(name){
 this.name = name;
 this.colors = ["red","blue","green"];
}
SuperType.prototype.sayName = function(){
 alert(this.name);
};
function SubType(name,age){
 SuperType.call(this,name); // 第二次调用SuperType()
 this.age = age;
}
SubType.prototype = new SuperType(); //第一次调用SuperType()
SubType.prototype.constructor = SubType;
SubType.prototype.sayAge = function(){
 alert(this.age);
}; 

function object(o){
  function F(){};
  F.prototype = o;
  return new F();
}
var person = {
  name: "Nicholas",
  friends: ["Shelby","Court","Van"]
};
var anotherPerson = object(person);
anotherPerson.name = "Greg";
anotherPerson.friends.push("Rob");

var yetAnotherPerson = object(person);
yetAnotherPerson.name = "Linda";
yetAnotherPerson.friends.push("Barbie");

alert(person.friends);//"Shelby,Court,Van,Rob,Barbie"

function object(o){
 function F(){};
 F.prototype = o;
 return new F();
}
var person = {
 name: "Nicholas",
 friends:["Shelby","Court","Van"]
};
var anotherPerson = Object.create(person);
anotherPerson.name = "Greg";
anotherPerson.friends.push("Rob");
var yetAnotherPerson = object(person);
yetAnotherPerson.name = "Linda";
yetAnotherPerson.friends.push("Barbie");
alert(person.friends);//"Shelby,Court,Van,Rob,Barbie"

var person = {
 name: "Nicholas",
 friends:["Shelby","Court","Van"]
};
var anotherPerson = Object.create(person,{
 name: {
  value: "Greg"
 }
});
alert(anotherPerson.name);//"Greg" 

if(typeof Object.create != "function"){
 (function(){
  var F = function(){};
  Object.create = function(o){
   if(arguments.length > 1){
    throw Error('Second argument noe supported');
   }
   if(o === null){
    throw Error("Cannot set a null [[Prototype]]");
   }
   if(typeof o != 'Object'){
    throw TypeError("Arguments must be an object");
   }
   F.prototype = o;
   return new F();
  }
 })();
} 

function object(o){
 function F(){};
 F.prototype = o;
 return new F();
}
function createAnother(original){
 var clone = object(original);//通过调用函数创建一个新对象
 clone.sayHi = function(){ //以某种方式来增强这个对象
  alert("hi");
 };
 return clone;//返回这个对象
}
var person = {
 name: "Nicholas",
 friends: ["Shelby","Court","Van"]
};
var anotherPerson = createAnother(person);
anotherPerson.sayHi();//"hi"

//这个例子中的高效率体现在它只调用了一次Super构造函数，并且因此避免了在SubType.prototype上面创建不必要的、多余的属性。与此同时，原型链还能保持不变。
function object(o){
 function F(){};
 F.prototype = o;
 return new F();
}
function inheritPrototype(subType,superType){
 var prototype = object(superType.prototype);//创建对象
 prototype.constructor = subType;//增强对象
 subType.prototype = prototype;//指定对象
}
function SuperType(name){
 this.name = name;
 this.colors = ["red","blue","green"];
}
SuperType.prototype.sayName = function(){
 alert(this.name);
};
function SubType(name,age){
 SuperType.call(this,name);
 this.age = age;
}
inheritPrototype(SubType,SuperType);
SubType.prototype.sayAge = function(){
 alert(this.age);
}