/* 最基本的單體模式 */ 
var her = {
name: 'Anna',
sex: 'women',
say: function(){
// 一些處理邏輯......
},
doing: function(){
// 另一些處理函數(shù)......
} 
}

var box = {
width: 0,
height: 0,
getArea: function(){
return this.width * this.width; // js中對(duì)象成的訪(fǎng)問(wèn)必須是顯示的，即this是不能省略的
},
init: function(w, h){
// width = w;
// height = h;這種方式相當(dāng)于定義了兩個(gè)全局變量，（沒(méi)加var聲明的變量為全局變量）
// 并不是對(duì)對(duì)象width和height的賦值
// 下面是正確的
this.width = w;
this.height = h;
}
} //box劃分了一個(gè)命名空間，命名空間里的變量只在空間里有效

var box = {
width:0,
height:0,//單體的變量
getArea:function(){
return width * height;// width，height其實(shí)并不是單體的變量，而是在init中定義的全局變量
}
init:function(w,h){
width = w;
height = h;
}
}// init中width，height其實(shí)并不是單體的變量
window.onload = function(){
var init = box.getArea();
alert(init);
}

var box = {
width:0,
height:0,
getArea:function(){
return width * height;
},
init:function(w,h){
width = w;
height = h;
}
}
window.onload = function(){
width = 0;
height = 0;
//or box.init(0,0);
var init = box.getArea();
alert(init);
}

var box = {
width: 0,
height: 0,
getArea: function(){
return width * height;//js中對(duì)象成的訪(fǎng)問(wèn)必須是顯示的，即this是不能省略的
},
init:function(w,h){
width = w;
height = h;
}
}//這里的width，height其實(shí)并不是單體的對(duì)象
window.onload = function(){
width = 0;
height = 0;
var width = box.getArea();
alert(width);
}

var box = {
width: 2,
height: 2,
getArea: function(){
return this.width * this.height;/ /js中對(duì)象成的訪(fǎng)問(wèn)必須是顯示的，即this是不能省略的
},
init:function(w,h){
this.width = w;
this.height = h;
}
}
window.onload = function(){
width = 0; // 不會(huì)影響單體中的局部變量也就是命名空間
height = 0; // 不會(huì)影響單體中的局部變量也就是命名空間
var width = box.getArea();
alert(width);
}

var her = (function(){
var name = 'Anna';
var sex = 'women';
return {
getArea: function(){
return name + 'is a' + sex;
},
init:function(b){
name = b;
}
}
})();
window.onload = function(){
her.name = 'Jock'; // 無(wú)法訪(fǎng)問(wèn)
alert(ger.getArea());
her.init('Lous');
alert(her.getArea());
}

// 利用單體的分支技術(shù)來(lái)定義XHR（XMLHttpRequest）對(duì)象,必須要用閉包才可以實(shí)現(xiàn)
var XHR = (function(){
//The three branches
var standard = {
cXHR:function(){
return new XMLHttpRequest();
} 
};
var activeXNew = {
cXHR:function(){
return new ActiveXObject('Msxml2.XMLHttp');
} 
};
var activeXOld = {
cXHR:function(){
return new ActiveXObject('Microsoft.XMLHttp');
} 
};
//To assign(分配) the branch, try each method;return whatever doesn't fail
var testObject;
try{
testObject = standard.cXHR();
return standard;// return this branch if no error was thrown 
}catch(e){
try{
testObject = activeXNew.cXHR();
return activeXNew;
}catch(e){
try{
testObject = activeXOld.cXHR();
return activeXOld;
}catch(e){
throw new Error('Create the XMLHttpRequestObject failed!'); 
}
}
}
})();
window.onload = function(){
alert(XHR.cXHR());
}