JQuery的extend扩展方法有两种形式：
形式一：
- jQuery.extend(target,[object1],[objectN])
这种中的target、object1、objectN都是Object类型。它的含义是将object1,objectN合并到target中,返回值为合并后的target,由此可以看出该方法合并后，是修改了target的结构的。如果想要得到合并的结果却又不想修改target的结构，可以如下使用下面：
- var object = $.extend({}, object1, object2);
下面介绍一些例子：
- <html>
- <head>
- <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
- </head>
- <body>
- <div id="log"></div>
- <script>
- var object1 = {
- apple: 0,
- banana: {weight: 52, price: 100},
- cherry: 97
- };
- var object2 = {
- banana: {price: 200},
- durian: 100
- };
- /* merge object2 into object1 */
- $.extend(object1, object2);
- var printObj = typeof JSON != "undefined" ? JSON.stringify : function(obj) {
- var arr = [];
- $.each(obj, function(key, val) {
- var next = key + ": ";
- next += $.isPlainObject(val) ? printObj(val) : val;
- arr.push( next );
- });
- return "{ " + arr.join(", ") + " }";
- };
- $("#log").append( printObj(object1) );
- </script>
- </body>
- </html>
结果是：{"apple":0,"banana":{"price":200},"cherry":97,"durian":100}
- <html>
- <head>
- <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
- </head>
- <body>
- <div id="log"></div>
- <script>
- var defaults = { validate: false, limit: 5, name: "foo" };
- var options = { validate: true, name: "bar" };
- /* merge defaults and options, without modifying defaults */
- var settings = $.extend({}, defaults, options);
- var printObj = typeof JSON != "undefined" ? JSON.stringify : function(obj) {
- var arr = [];
- $.each(obj, function(key, val) {
- var next = key + ": ";
- next += $.isPlainObject(val) ? printObj(val) : val;
- arr.push( next );
- });
- return "{ " + arr.join(", ") + " }";
- };
- $("#log").append( "<div><b>defaults -- </b>" + printObj(defaults) + "</div>" );
- $("#log").append( "<div><b>options -- </b>" + printObj(options) + "</div>" );
- $("#log").append( "<div><b>settings -- </b>" + printObj(settings) + "</div>" );
- </script>
- </body>
- </html>
结果是：defaults -- {"validate":false,"limit":5,"name":"foo"}
options -- {"validate":true,"name":"bar"}
settings -- {"validate":true,"limit":5,"name":"bar"}
形式二：
- jQuery.extend([deep], target, object1, [objectN])
其中deep是Boolean类型，target、object1、objectN是Object类型。它的含义是：如果deep设为true，则递归合并将object1,objectN合并到target中,返回值为合并后的target。
下面举个例子：
- <html>
- <head>
- <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
- </head>
- <body>
- <div id="log"></div>
- <script>
- var object1 = {
- apple: 0,
- banana: {weight: 52, price: 100},
- cherry: 97
- };
- var object2 = {
- banana: {price: 200},
- durian: 100
- };
- /* merge object2 into object1, recursively */
- $.extend(true, object1, object2);
- var printObj = typeof JSON != "undefined" ? JSON.stringify : function(obj) {
- var arr = [];
- $.each(obj, function(key, val) {
- var next = key + ": ";
- next += $.isPlainObject(val) ? printObj(val) : val;
- arr.push( next );
- });
- return "{ " + arr.join(", ") + " }";
- };
- $("#log").append( printObj(object1) );
- </script>
- </body>
- </html>
运行结果：{"apple":0,"banana":{"weight":52,"price":200},"cherry":97,"durian":100}