js面向对象高级编程

面向对象的组成

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
var arr = [];
arr.number = 10; //对象下面的变量：叫做对象的属性
//alert( arr.number );
//alert( arr.length );
arr.test = function(){ //对象下面的函数 : 叫做对象的方法
alert(123);
};
arr.test();
arr.push();
arr.sort();
</script>
</head>
<body>
</body>
</html>

创建第一个面向对象程序

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
//var obj = {};
var obj = new Object(); //创建了一个空的对象
obj.name = '小明'; //属性
obj.showName = function(){ //方法
alert(this.name);
};
obj.showName();
var obj2 = new Object(); //创建了一个空的对象
obj2.name = '小强'; //属性
obj2.showName = function(){ //方法
alert(this.name);
};
obj2.showName();
</script>
</head>
<body>
</body>
</html>

工厂方式

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
//工厂方式 : 封装函数
function createPerson(name){
//1.原料
var obj = new Object();
//2.加工
obj.name = name;
obj.showName = function(){
alert( this.name );
};
//3.出场
return obj;
}
var p1 = createPerson('小明');
p1.showName();
var p2 = createPerson('小强');
p2.showName();
</script>
</head>
<body>
</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
//当new去调用一个函数 : 这个时候函数中的this就是创建出来的对象,而且函数的的返回值直接就是this啦(隐式返回)
//new后面调用的函数 : 叫做构造函数
function CreatePerson(name){
this.name = name;
this.showName = function(){
alert( this.name );
};
}
var p1 = new CreatePerson('小明');
//p1.showName();
var p2 = new CreatePerson('小强');
//p2.showName();
alert( p1.showName == p2.showName ); //false
var arr = new Array();
var date = new Date();
</script>
</head>
<body>
</body>
</html>

对象的引用

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
/*var a = [1,2,3];
var b = [1,2,3];
alert( a == b ); //false*/
//var a = 5;
//var b = a;
//b += 3;
////alert(b); //8
//alert(a); //5 基本类型 : 赋值的时候只是值的复制
//var a = [1,2,3];
//var b = a;
//b.push(4);
////alert(b); //[1,2,3,4]
//alert(a); //[1,2,3,4] 对象类型 : 赋值不仅是值的复制，而且也是引用的传递
//var a = [1,2,3];
//var b = a;
//b = [1,2,3,4];
////alert(b); //[1,2,3,4]
//alert(a); //[1,2,3]
//var a = 5;
//var b = 5;
//
//alert(a == b); //基本类型 : 值相同就可以
//var a = [1,2,3];
//var b = [1,2,3];
//alert( a == b ); //false //对象类型 : 值和引用都相同才行
var a = [1,2,3];
var b = a;
alert( a==b ); //true
</script>
</head>
<body>
</body>
</html>

原型

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
//原型 : 去改写对象下面公用的方法或者属性 , 让公用的方法或者属性在内存中存在一份 ( 提高性能 )
//原型 : CSS中的class
//普通方法 : CSS中的style
//原型 : prototype : 要写在构造函数的下面
/*var arr = [1,2,3,4,5];
var arr2 = [2,2,2,2,2];
arr.sum = function(){
var result = 0;
for(var i=0;i<this.length;i++){
result += this[i];
}
return result;
};
arr2.sum = function(){
var result = 0;
for(var i=0;i<this.length;i++){
result += this[i];
}
return result;
};
//alert( arr.sum() ); //15
//alert( arr2.sum() ); //10*/
var arr = [1,2,3,4,5];
var arr2 = [2,2,2,2,2];
Array.prototype.sum = function(){
var result = 0;
for(var i=0;i<this.length;i++){
result += this[i];
}
return result;
};
alert( arr.sum() ); //15
alert( arr2.sum() ); //10
</script>
</head>
<body>
</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
var arr = [];
//arr.number = 10;
Array.prototype.number = 20;
alert(arr.number);
</script>
</head>
<body>
</body>
</html>

工厂方法之原型

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
//当new去调用一个函数 : 这个时候函数中的this就是创建出来的对象,而且函数的的返回值直接就是this啦(隐式返回)
//new后面调用的函数 : 叫做构造函数
function CreatePerson(name){
this.name = name;
}
CreatePerson.prototype.showName = function(){
alert( this.name );
};
var p1 = new CreatePerson('小明');
//p1.showName();
var p2 = new CreatePerson('小强');
//p2.showName();
alert( p1.showName == p2.showName ); //true
var arr = new Array();
var date = new Date();
</script>
</head>
<body>
</body>
</html>

面向对象的写法

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
function 构造函数(){
this.属性
}
构造函数.原型.方法 = function(){};
var 对象1 = new 构造函数();
对象1.方法();
</script>
</head>
<body>
</body>
</html>

面向对象的选项卡

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style>
#div1 div{ width:200px; height:200px; border:1px #000 solid; display:none;}
.active{ background:red;}
</style>
<script>
/*window.onload = function(){
var oParent = document.getElementById('div1');
var aInput = oParent.getElementsByTagName('input');
var aDiv = oParent.getElementsByTagName('div');
for(var i=0;i<aInput.length;i++){
aInput[i].index = i;
aInput[i].onclick = function(){
for(var i=0;i<aInput.length;i++){
aInput[i].className = '';
aDiv[i].style.display = 'none';
}
this.className = 'active';
aDiv[this.index].style.display = 'block';
};
}
};*/
//先变型:
//尽量不要出现函数嵌套函数
//可以有全局变量
//把onload中不是赋值的语句放到单独函数中
var oParent = null;
var aInput = null;
var aDiv = null;
window.onload = function(){
oParent = document.getElementById('div1');
aInput = oParent.getElementsByTagName('input');
aDiv = oParent.getElementsByTagName('div');
init();
};
function init(){
for(var i=0;i<aInput.length;i++){
aInput[i].index = i;
aInput[i].onclick = change;
}
}
function change(){
for(var i=0;i<aInput.length;i++){
aInput[i].className = '';
aDiv[i].style.display = 'none';
}
this.className = 'active';
aDiv[this.index].style.display = 'block';
}
</script>
</head>
<body>
<div id="div1">
<input class="active" type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<div style="display:block">11111</div>
<div>22222</div>
<div>33333</div>
</div>
</body>
</html>

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style>
#div1 div{ width:200px; height:200px; border:1px #000 solid; display:none;}
.active{ background:red;}
</style>
<script>
/*window.onload = function(){
var oParent = document.getElementById('div1');
var aInput = oParent.getElementsByTagName('input');
var aDiv = oParent.getElementsByTagName('div');
for(var i=0;i<aInput.length;i++){
aInput[i].index = i;
aInput[i].onclick = function(){
for(var i=0;i<aInput.length;i++){
aInput[i].className = '';
aDiv[i].style.display = 'none';
}
this.className = 'active';
aDiv[this.index].style.display = 'block';
};
}
};*/
//先变型:
//尽量不要出现函数嵌套函数
//可以有全局变量
//把onload中不是赋值的语句放到单独函数中
/*var oParent = null;
var aInput = null;
var aDiv = null;
window.onload = function(){
oParent = document.getElementById('div1');
aInput = oParent.getElementsByTagName('input');
aDiv = oParent.getElementsByTagName('div');
init();
};
function init(){
for(var i=0;i<aInput.length;i++){
aInput[i].index = i;
aInput[i].onclick = change;
}
}
function change(){
for(var i=0;i<aInput.length;i++){
aInput[i].className = '';
aDiv[i].style.display = 'none';
}
this.className = 'active';
aDiv[this.index].style.display = 'block';
}*/
//改成面向对象:
//全局变量就是属性
//函数就是方法
//Onload中创建对象
//改this指向问题 : 事件或者是定时器,尽量让面向对象中的this指向对象
window.onload = function(){
var t1 = new Tab();
t1.init();
};
function Tab(){
this.oParent = document.getElementById('div1');
this.aInput = this.oParent.getElementsByTagName('input');
this.aDiv = this.oParent.getElementsByTagName('div');
}
Tab.prototype.init = function(){
var This = this;
for(var i=0;i<this.aInput.length;i++){
this.aInput[i].index = i;
this.aInput[i].onclick = function(){
This.change(this);
};
}
};
Tab.prototype.change = function(obj){
for(var i=0;i<this.aInput.length;i++){
this.aInput[i].className = '';
this.aDiv[i].style.display = 'none';
}
obj.className = 'active';
this.aDiv[obj.index].style.display = 'block';
};
</script>
</head>
<body>
<div id="div1">
<input class="active" type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<div style="display:block">11111</div>
<div>22222</div>
<div>33333</div>
</div>
</body>
</html>

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style>
#div1 div,#div2 div{ width:200px; height:200px; border:1px #000 solid; display:none;}
.active{ background:red;}
</style>
<script>
/*var arr = [4,7,1,3];
arr.sort(); // 1 3 4 7
var arr2 = [4,7,1,3];
arr2.push(5);
arr2.sort(); // 1 3 4 5 7
*/
window.onload = function(){
var t1 = new Tab('div1');
t1.init();
t1.autoPlay();
var t2 = new Tab('div2');
t2.init();
t2.autoPlay();
};
function Tab(id){
this.oParent = document.getElementById(id);
this.aInput = this.oParent.getElementsByTagName('input');
this.aDiv = this.oParent.getElementsByTagName('div');
this.iNow = 0;
}
Tab.prototype.init = function(){
var This = this;
for(var i=0;i<this.aInput.length;i++){
this.aInput[i].index = i;
this.aInput[i].onclick = function(){
This.change(this);
};
}
};
Tab.prototype.change = function(obj){
for(var i=0;i<this.aInput.length;i++){
this.aInput[i].className = '';
this.aDiv[i].style.display = 'none';
}
obj.className = 'active';
this.aDiv[obj.index].style.display = 'block';
};
Tab.prototype.autoPlay = function(){
var This = this;
setInterval(function(){
if(This.iNow == This.aInput.length-1){
This.iNow = 0;
}
else{
This.iNow++;
}
for(var i=0;i<This.aInput.length;i++){
This.aInput[i].className = '';
This.aDiv[i].style.display = 'none';
}
This.aInput[This.iNow].className = 'active';
This.aDiv[This.iNow].style.display = 'block';
},2000);
};
</script>
</head>
<body>
<div id="div1">
<input class="active" type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<div style="display:block">11111</div>
<div>22222</div>
<div>33333</div>
</div>
<div id="div2">
<input class="active" type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<div style="display:block">11111</div>
<div>22222</div>
<div>33333</div>
</div>
</body>
</html>

面向对象的拖拽

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style>
#div1 div,#div2 div{ width:200px; height:200px; border:1px #000 solid; display:none;}
.active{ background:red;}
</style>
<script>
/*var arr = [4,7,1,3];
arr.sort(); // 1 3 4 7
var arr2 = [4,7,1,3];
arr2.push(5);
arr2.sort(); // 1 3 4 5 7
*/
window.onload = function(){
var t1 = new Tab('div1');
t1.init();
t1.autoPlay();
var t2 = new Tab('div2');
t2.init();
t2.autoPlay();
};
function Tab(id){
this.oParent = document.getElementById(id);
this.aInput = this.oParent.getElementsByTagName('input');
this.aDiv = this.oParent.getElementsByTagName('div');
this.iNow = 0;
}
Tab.prototype.init = function(){
var This = this;
for(var i=0;i<this.aInput.length;i++){
this.aInput[i].index = i;
this.aInput[i].onclick = function(){
This.change(this);
};
}
};
Tab.prototype.change = function(obj){
for(var i=0;i<this.aInput.length;i++){
this.aInput[i].className = '';
this.aDiv[i].style.display = 'none';
}
obj.className = 'active';
this.aDiv[obj.index].style.display = 'block';
};
Tab.prototype.autoPlay = function(){
var This = this;
setInterval(function(){
if(This.iNow == This.aInput.length-1){
This.iNow = 0;
}
else{
This.iNow++;
}
for(var i=0;i<This.aInput.length;i++){
This.aInput[i].className = '';
This.aDiv[i].style.display = 'none';
}
This.aInput[This.iNow].className = 'active';
This.aDiv[This.iNow].style.display = 'block';
},2000);
};
</script>
</head>
<body>
<div id="div1">
<input class="active" type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<div style="display:block">11111</div>
<div>22222</div>
<div>33333</div>
</div>
<div id="div2">
<input class="active" type="button" value="1">
<input type="button" value="2">
<input type="button" value="3">
<div style="display:block">11111</div>
<div>22222</div>
<div>33333</div>
</div>
</body>
</html>

包装对象

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
/*function Aaa(){
this.name = '小明';
}
Aaa.prototype.showName = function(){
alert( this.name );
};
var a1 = new Aaa();
a1.showName();
var arr = new Array();
arr.push();
arr.sort();
//在JS源码 : 系统对象也是基于原型的程序
function Array(){
this.lenglth = 0;
}
Array.prototype.push = function(){};
Array.prototype.sort = function(){};*/
//尽量不要去修改或者添加系统对象下面的方法和属性
var arr = [1,2,3];
Array.prototype.push = function(){
//this : 1,2,3
//arguments : 4,5,6
for(var i=0;i<arguments.length;i++){
this[this.length] = arguments[i]
}
return this.length;
};
arr.push(4,5,6);
alert( arr );
//pop shift unshift splice sort
</script>
</head>
<body>
</body>
</html>

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
/*var str = 'hello';
alert( typeof str );
str.charAt(0);
str.indexOf('e');*/
//null undefined
//包装对象 : 基本类型都有自己对应的包装对象 : String Number Boolean
/*var str = new String('hello');
//alert( typeof str );
alert(str.charAt(1));
String.prototype.charAt = function(){};*/
//var str = 'hello';
//str.charAt(0); //基本类型会找到对应的包装对象类型，然后包装对象把所有的属性和方法给了基本类型，然后包装对象消失
/*var str = 'hello';
String.prototype.lastValue = function(){
return this.charAt(this.length-1);
};
alert( str.lastValue() ); //o*/
var str = 'hello';
str.number = 10;
alert( str.number ); //undefined
</script>
</head>
<body>
</body>
</html>

原型链

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//原型链 : 实例对象与原型之间的连接，叫做原型链
//原型链的最外层 : Object.prototype
function Aaa(){
//this.num = 20;
}
//Aaa.prototype.num = 10;
Object.prototype.num = 30;
var a1 = new Aaa();
alert(a1.num);
</script>
</head>
<body>
</body>
</html>

hasOwnProperty

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//hasOwnProperty : 看是不是对象自身下面的属性
var arr = [];
arr.num = 10;
Array.prototype.num2 = 20;
//alert( arr.hasOwnProperty('num') ); //true
alert( arr.hasOwnProperty('num2') ); //false
</script>
</head>
<body>
</body>
</html>

constructor

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//constructor : 查看对象的构造函数
/*function Aaa(){
}
var a1 = new Aaa();
alert( a1.constructor ); //Aaa
var arr = [];
alert( arr.constructor == Array ); //true*/
/*function Aaa(){
}
//Aaa.prototype.constructor = Aaa; //每一个函数都会有的，都是自动生成的
//Aaa.prototype.constructor = Array;
var a1 = new Aaa();
alert( a1.hasOwnProperty == Object.prototype.hasOwnProperty ); //true*/
/*function Aaa(){
}
Aaa.prototype.name = '小明';
Aaa.prototype.age = 20;
Aaa.prototype = {
constructor : Aaa,
name : '小明',
age : 20
};
var a1 = new Aaa();
alert( a1.constructor );*/
function Aaa(){
}
Aaa.prototype.name = 10;
Aaa.prototype.constructor = Aaa;
for( var attr in Aaa.prototype ){
alert(attr);
}
</script>
</head>
<body>
</body>
</html>

instanceof

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//instanceof : 对象与构造函数在原型链上是否有关系
function Aaa(){
}
var a1 = new Aaa();
//alert( a1 instanceof Object ); //true
var arr = [];
alert( arr instanceof Array );
</script>
</head>
<body>
</body>
</html>

toString

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//toString() : 系统对象下面都是自带的 , 自己写的对象都是通过原型链找object下面的
/*var arr = [];
alert( arr.toString == Object.prototype.toString ); //false*/
/*function Aaa(){
}
var a1 = new Aaa();
alert( a1.toString == Object.prototype.toString ); //true*/
//toString() : 把对象转成字符串
/*var arr = [1,2,3];
Array.prototype.toString = function(){
return this.join('+');
};
alert( arr.toString() ); //'1,2,3'*/
//var num = 255;
//alert( num.toString(16) ); //'ff'
//利用toString做类型的判断 :
/*var arr = [];
alert( Object.prototype.toString.call(arr) == '[object Array]' ); */ //'[object Array]'
window.onload = function(){
var oF = document.createElement('iframe');
document.body.appendChild( oF );
var ifArray = window.frames[0].Array;
var arr = new ifArray();
//alert( arr.constructor == Array ); //false
//alert( arr instanceof Array ); //false
alert( Object.prototype.toString.call(arr) == '[object Array]' ); //true
};
</script>
</head>
<body>
</body>
</html>

继承

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//继承 : 子类不影响父类，子类可以继承父类的一些功能 ( 代码复用 )
//属性的继承 : 调用父类的构造函数 call
//方法的继承 : for in : 拷贝继承 (jquery也是采用拷贝继承extend)
function CreatePerson(name,sex){ //父类
this.name = name;
this.sex = sex;
}
CreatePerson.prototype.showName = function(){
alert( this.name );
};
var p1 = new CreatePerson('小明','男');
//p1.showName();
function CreateStar(name,sex,job){ //子类
CreatePerson.call(this,name,sex);
this.job = job;
}
//CreateStar.prototype = CreatePerson.prototype;
extend( CreateStar.prototype , CreatePerson.prototype );
CreateStar.prototype.showJob = function(){
};
var p2 = new CreateStar('黄晓明','男','演员');
p2.showName();
function extend(obj1,obj2){
for(var attr in obj2){
obj1[attr] = obj2[attr];
}
}
</script>
</head>
<body>
</body>
</html>

对象的复制

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
/*var a = {
name : '小明'
};
var b = a;
b.name = '小强';
alert( a.name );*/
/*var a = {
name : '小明'
};
//var b = a;
var b = {};
extend( b , a );
b.name = '小强';
alert( a.name );
function extend(obj1,obj2){
for(var attr in obj2){
obj1[attr] = obj2[attr];
}
}*/
var a = [1,2,3];
var b = a;
//b.push(4);
b = [1,2,3,4];
alert(a);
</script>
</head>
<body>
</body>
</html>

继承的拖拽

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style>
#div1{ width:100px; height:100px; background:red; position:absolute;}
#div2{ width:100px; height:100px; background:yellow; position:absolute; left:100px;}
</style>
<script>
window.onload = function(){
var d1 = new Drag('div1');
d1.init();
var d2 = new ChildDrag('div2');
d2.init();
};
function Drag(id){ //父类
this.obj = document.getElementById(id);
this.disX = 0;
this.disY = 0;
}
Drag.prototype.init = function(){
var This = this;
this.obj.onmousedown = function(ev){
var ev = ev || window.event;
This.fnDown(ev);
document.onmousemove = function(ev){
var ev = ev || window.event;
This.fnMove(ev);
};
document.onmouseup = function(){
This.fnUp();
};
return false;
};
};
Drag.prototype.fnDown = function(ev){
this.disX = ev.clientX - this.obj.offsetLeft;
this.disY = ev.clientY - this.obj.offsetTop;
};
Drag.prototype.fnMove = function(ev){
this.obj.style.left = ev.clientX - this.disX + 'px';
this.obj.style.top = ev.clientY - this.disY + 'px';
};
Drag.prototype.fnUp = function(){
document.onmousemove = null;
document.onmouseup = null;
};
function ChildDrag(id){ //子类
Drag.call(this,id);
}
extend( ChildDrag.prototype , Drag.prototype );
ChildDrag.prototype.fnMove = function(ev){
var L = ev.clientX - this.disX;
var T = ev.clientY - this.disY;
if(L<0){
L = 0;
}
else if(L>document.documentElement.clientWidth - this.obj.offsetWidth){
L = document.documentElement.clientWidth - this.obj.offsetWidth;
}
this.obj.style.left = L + 'px';
this.obj.style.top = T + 'px';
};
function extend(obj1,obj2){
for(var attr in obj2){
obj1[attr] = obj2[attr];
}
}
</script>
</head>
<body>
<div id="div1"></div>
<div id="div2"></div>
</body>
</html>

类式继承

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
//类 : JS是没有类的概念的 , 把JS中的构造函数看做的类
//要做属性和方法继承的时候，要分开继承
function Aaa(){ //父类
this.name = [1,2,3];
}
Aaa.prototype.showName = function(){
alert( this.name );
};
function Bbb(){ //子类
Aaa.call(this);
}
var F = function(){};
F.prototype = Aaa.prototype;
Bbb.prototype = new F();
Bbb.prototype.constructor = Bbb; //修正指向问题
var b1 = new Bbb();
//b1.showName();
//alert( b1.name );
//alert( b1.constructor );
b1.name.push(4);
var b2 = new Bbb();
alert( b2.name );
</script>
</head>
<body>
</body>
</html>

原型继承

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
var a = {
name : '小明'
};
var b = cloneObj(a);
b.name = '小强';
//alert( b.name );
alert( a.name );
function cloneObj(obj){
var F = function(){};
F.prototype = obj;
return new F();
}
拷贝继承: 通用型的有new或无new的时候都可以
类式继承: new构造函数
原型继承: 无new的对象
</script>
</head>
<body>
</body>
</html>

w3

js面向对象高级编程