1 Array.prototype.remove = function (s) {  2     for (var i = 0; i < this.length; i++) {  3         if (s == this[i])  4             this.splice(i, 1);  5     }  6 }  7   8 /**  9  * Simple Map 10  * 11  * 12  * var m = new Map(); m.put('key','value'); ... var s = ""; 13  * m.each(function(key,value,index){ s += index+":"+ key+"="+value+"\n"; }); 14  * alert(s); 15  * 16  * @author dewitt 17  * @date 2008-05-24 18  */ 19 function Map() { 20     /** 存放键的数组(遍历用到) */ 21     this.keys = new Array(); 22     /** 存放数据 */ 23     this.data = new Object(); 24  25     this.maxSize = arguments[0] ? arguments[0] : 0; 26  27     /** 28      * 放入一个键值对 29      * 30      * @param {String} 31      *            key 32      * @param {Object} 33      *            value 34      */ 35     this.put = function (key, value) { 36         if (this.data[key] == null) { 37             this.keys.push(key); 38         } 39         this.data[key] = value; 40     }; 41  42     /** 43      * 放入一个键值对, FIFO容量移除策略 44      * 45      * @param {String} 46      *            key 47      * @param {Object} 48      *            value 49      */ 50     this.putQ = function (key, value) { 51         if (this.data[key] == null) { 52             this.keys.push(key); 53         } 54         this.data[key] = value; 55         this.trimToSize(this.maxSize); 56     }; 57  58     this.trimToSize = function (max_size) { 59         var tmpSize = this.size; 60         if (tmpSize > max_size) { 61             this.each(function (key, value, index) { 62                 if (index < tmpSize - max_size) { 63                     this.remove(key); 64                 } 65             }); 66         } 67     } 68  69     /** 70      * 获取某键对应的值 71      * 72      * @param {String} 73      *            key 74      * @return {Object} value 75      */ 76     this.get = function (key) { 77         return this.data[key]; 78     }; 79  80     /** 81      * 删除一个键值对 82      * 83      * @param {String} 84      *            key 85      */ 86     this.remove = function (key) { 87         this.keys.remove(key); 88         this.data[key] = null; 89     }; 90  91     /** 92      * 遍历Map,执行处理函数 93      * 94      * @param {Function} 95      *            回调函数 function(key,value,index){..} 96      */ 97     this.each = function (fn) { 98         if (typeof fn != 'function') { 99             return;100         }101         var len = this.keys.length;102         for (var i = 0; i < len; i++) {103             var k = this.keys[i];104             fn(k, this.data[k], i);105         }106     };107 108     /**109      * 获取键值数组(类似Java的entrySet())110      *111      * @return 键值对象{key,value}的数组112      */113     this.entrys = function () {114         var len = this.keys.length;115         var entrys = new Array(len);116         for (var i = 0; i < len; i++) {117             entrys[i] = {118                 key: this.keys[i],119                 value: this.data[i]120             };121         }122         return entrys;123     };124 125     /**126      * 判断Map是否为空127      */128     this.isEmpty = function () {129         return this.keys.length == 0;130     };131 132     /**133      * 获取键值对数量134      */135     this.size = function () {136         return this.keys.length;137     };138 139     /**140      * 重写toString141      */142     this.toString = function () {143         var s = "{";144         for (var i = 0; i < this.keys.length; i++, s += ',') {145             var k = this.keys[i];146             s += k + "=" + JSON.stringify(this.data[k]);147         }148         s += "}";149         return s;150     };151 }152 153 function testMap() {154     var m = new Map();155     m.put('key1', 'v1');156     m.put('key2', 'v2');157     m.put('key3', 'v3');158     m.put('key4', 'v4');159     alert("init:" + m);160 161     m.put('key1', 'v5');162     alert("set key1:" + m);163 164     m.remove("key2");165     alert("remove key2: " + m);166 167     var s = "";168     m.each(function (key, value, index) {169         if (index < 2) {170             m.remove(key);171         }172     });173 174     m.each(function (key, value, index) {175         s += index + ":" + key + "=" + value + "\n";176     });177     alert(s);178 }

 prototype是原型，通过原型调用方法，后续会总结一下。

 　

　整个map相当于一个json对象,map = {keys : arr,values : abc,}  就是这种形式。通过map来存取数据，但不能存储大数据。

   这就是数据结构，太重要了。