1 //标记已经加载成功的个数
 2 var REQ_TOTAL = 0;
 3 //模块导出
 4 window.exports = {};
 5 //记录各个模块的顺序
 6 var exp_arr = [];
 7 
 8 //判断是否数组
 9 function isArray(param) {
10     return param instanceof Array;
11 }
12 
13 //require 真正实现
14 function require(arr, callback) {
15 
16     var req_list;
17 
18     if(isArray(arr)) {
19         req_list = arr;
20     } else {
21         req_list = [arr];
22     }
23     var req_len = req_list.length;
24 
25     //模块逐个加载
26     for(var i=0;i<req_len;i++) {
27         var req_item = req_list[i];
28 
29         var $script = createScript(req_item, i);
30 
31         var $node = document.querySelector(‘head‘);
32 
33         (function($script) {
34             //检测script 的onload事件
35             $script.onload = function() {
36                 REQ_TOTAL++;
37 
38                 var script_index = $script.getAttribute(‘index‘);
39 
40                 exp_arr[script_index] = exports;
41 
42                 window.exports = {};
43 
44                 //所有链接加载成功后，执行callback
45                 if(REQ_TOTAL == req_len) {
46                     callback && callback.apply(exports, exp_arr);
47 
48              
49                 }
50 
51             }
52 
53             $node.appendChild($script);
54         })($script);
55 
56     }
57 
58 }
59 
60 //创建一个script标签
61 function createScript(src, index) {
62     var $script = document.createElement(‘script‘);
63 
64     $script.setAttribute(‘src‘, src);
65     $script.setAttribute(‘index‘, index);
66 
67     return $script;
68 }

1 exports.define = {
2     topic: ‘my export‘,
3     desc: ‘this is other way to define ‘,
4     sayHello: function() {
5         console.log(‘topic ‘ + this.topic + this.desc);
6     }
7 }

1 exports.define = {
2     name: ‘xm‘,
3     age: 22,
4     info: function() {
5         console.log(‘topic ‘ + this.name + this.age);
6     }
7 }

1 //测试demo
2 require([‘../res/define.js‘, ‘../res/define2.js‘], function(def, def2) {
3     def.define.sayHello();
4 
5     def2.define.info();
6 });