C.js代码:
/** * 有BUG */ (function (global) { var _id; _map; _length; global.C = () { _map = {}; _length = 0; }; global.C.prototype = { setId: (id) { _id = id; },getId: () { return _id; },put: (key,value) { if (!_map.hasOwnProperty(key)) { _length++; } _map[key] = value; },get: (key) { if (_map.hasOwnProperty(key)) { _map[key]; } return null; },}; global.C.prototype.constructor = global.C; })(window);
错误原因:代码中_id、_map、_length变量是C的所有实例共用的。
D.js代码:
* * 无BUG (global) { global.D = () { this._map = {}; this._length = 0; }; global.D.prototype = (id) { this._id =this._id; },1)">._map.hasOwnProperty(key)) { this._length++; } this._map[key] =if (._map[key]; } global.D; })(window);
test.html代码:
<!DOCTYPE html> <html> <head> <title>JS闭包测试</title> <meta charset="utf-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width,initial-scale=1"> <style type="text/css"> </style> <script type="text/javascript" src="jquery-1.7.1.js"></script> <script type="text/javascript" src="C.js"></script> <script type="text/javascript" src="D.js"></script> </head> <body> <input type="button" value="测试1" onclick="test()" /> <div id="div" style="height:800px;"></div> <script type="text/javascript"> var div = $("#div"); log(msg) { div.append(msg + " "); } logLine(msg) { div.append(msg + "<br />"//测试 test() { var c1 = new C(); var c2 = var d1 = D(); var d2 = D(); c1.setId("id1"); c2.setId("id2"); d1.setId("id1"); d2.setId("id2"); logLine(c1.getId()); logLine(c2.getId()); logLine(d1.getId()); logLine(d2.getId()); debugger; c1.put("key1","value1"); c2.put("key1","value2"); d1.put("key1",1)">); d2.put("key1",1)">); logLine(c1.get("key1")); logLine(c2.get("key1")); logLine(d1.get("key1")); logLine(d2.get("key1")); } </script> </body> </html>
测试截图: