1.合并多个对象（不加判断条件 --> 对象属性覆盖）
<span style="font-size:18px;">//用法: jQuery.extend(obj1,obj2,obj3,..)var Css1={size: "10px",style: "oblique"}
var Css2={size: "12px",style: "oblique",weight: "bolder"}
$.jQuery.extend(Css1,Css2)
</span>
//结果:Css1的size属性被覆盖,而且继承了Css2的weight属性
// Css1 = {size: "12px",style: "oblique",weight: "bolder"}
2.深度嵌套对象 （加判断条件-->是否属性合并覆盖）
<span style="font-size:18px;">
jQuery.extend(
{ name: “John”, location: { city: “Boston” } },{ last: “Resig”, location: { state: “MA” } }
);
// 结果:// => { name: “John”, last: “Resig”, location: { state: “MA” } }
// 新的更深入的 .extend()
jQuery.extend(
true, { name: “John”, location: { city: “Boston” } },
{ last: “Resig”, location: { state: “MA” } });
// 结果
// => { name: “John”, last: “Resig”, location: { city: “Boston”, state: “MA” } }
</span>3.可以给jQuery添加静态方法（自定义方法 $.add() 调用方法）
<span style="font-size:18px;"><html>
<head>
<title></title>
</head>
<body>
<script type="text/javascript" src="jquery.2.0.3.js"></script>
<script type="text/javascript">
$.extend({
add:function(a,b){return a+b;},
minus:function(a,b){return a-b},
multiply:function(a,b){return a*b;},
divide:function(a,b){return Math.floor(a/b);}
});
var sum = $.add(3,5)+$.minus(3,5)+$.multiply(3,5)+$.divide(5,7);
console.log(sum);
</script>
</body>
</html></span>