prototype & call 实现继承

 <script>
	var Person = function(name, age) {
		this.name = name;
		this.age = age;
	}
	
	
	
	Person.prototype.SayHello = function () {
		alert(this.name + "," + this.age);
	};
	
	var Programmer = function (name, age, salary) {
		Person.call(this, name, age);
		this.salary = salary;
	};


	Programmer.prototype = new Person();
	var pro = new Programmer("kym", 21, 500);
	pro.SayHello();
</script>

 <script> var Person = function(name, age) { this.name = name; this.age = age; }   Person.prototype.SayHello = function () {alert(this.name + "," + this.age);};var Programmer = function (name, age, salary) {Person.call(this, name, age);this.salary = salary;};Programmer.prototype = new Person();var pro = new Programmer("kym", 21, 500);pro.SayHello();</script>
 <script>var Person = function(name, age) {this.name = name;this.age = age;}Person.prototype.SayHello = function () {alert(this.name + "," + this.age);};var Programmer = function (name, age, salary) {Person.call(this, name, age);this.salary = salary;};
 
Programmer.prototype = new Person();var pro = new Programmer("kym", 21, 500);pro.SayHello();</script>

<script> var Person = function(name, age) { this.name = name; this.age = age; }   Person.prototype.SayHello = function () {alert(this.name + "," + this.age);};var Programmer = function (name, age, salary) {Person.call(this, name, age);this.salary = salary;};Programmer.prototype = new Person();var pro = new Programmer("kym", 21, 500);pro.SayHello();</script>
 <script>var Person = function(name, age) {this.name = name;this.age = age;}Person.prototype.SayHello = function () {alert(this.name + "," + this.age);};var Programmer = function (name, age, salary) {Person.call(this, name, age);this.salary = salary;};
 
Programmer.prototype = new Person();var pro = new Programmer("kym", 21, 500);pro.SayHello();</script>