jQuery $.extend()用法总结

1.合并多个对象

var Css1={size: "10px",style: "oblique"}
var Css2={size: "12px",style: "oblique",weight: "bolder"}
$.jQuery.extend(Css1,Css2) 

//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

jQuery.extend(
{ name: “John”, location: { city: “Boston” } },
{ last: “Resig”, location: { state: “MA” } }
); 

 //结果：{ name: “John”, last: “Resig”, location: { state: “MA” } }

--深层合并
jQuery.extend( true,
{ name: “John”, location: { city: “Boston” } },
{ last: “Resig”, location: { state: “MA” } }
); 

//结果：
{ name: “John”, last: “Resig”,
 location: { city: “Boston”, state: “MA” } }  

3.可以给jQuery添加静态方法。

$.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); 

4.

jQuery为开发插件提拱了两个方法，分别是： 
jQuery.fn.extend(object);  //扩展实例
jQuery.extend(object);  //扩展静态方法

$.fn.extend({name:function(){console.log("1")},age:12})
a=$(‘body‘)
a.name() //1

ps: 扩展插件还有种简单的方式，如下，因为jQuery 中 jQuery.fn.init.prototype = jQuery.fn;

$.fn.display=function{}