js Map

// js 实现的 map 对象
// js中使用键值对一直是比较困难的，通过Array自定义方式来
// 实现js 中使用 map对象的，以此来达到js使用键值对的目的
// 使用示例
//  1. 引入 jsMap.js
//  2. 定义map对象  var map = new Map();
//  3. 操作map 对象
//     例如：map.put('key1','keyValue');
//   map 支持的方法如下 
//  get(key) 获得key对应的value
//  getAll() 获得所有的的value
//  getAllKey()  获得所有的的key
//  put(key,keyvalue)
//  remove(key)
//  size()
//  isEmpty()

function Map() {

 this.arr = new Array();
 this.get = get;
 this.getAll = getAll;
 this.getAllKey = getAllKey;
 this.put = put;
 this.remove = remove;
 this.size = size;
 this.isEmpty = isEmpty;

 var struct = function(key, value) {
  this.key = key;
  this.value = value;
 }

 var put = function(key, value){
  for (var i = 0; i < this.arr.length; i++) {
   if ( this.arr[i].key === key ) {
    this.arr[i].value = value;
    return;
   }
  }
   this.arr[this.arr.length] = new struct(key, value);
 }

 var get = function(key) {
  for (var i = 0; i < this.arr.length; i++) {
   if ( this.arr[i].key === key ) {
     return this.arr[i].value;
   }
  }
  return null;
 }

var getAll = function() {
      var str="";

      for (var i = 0; i < this.arr.length; i++) {
             str += this.arr[i].value;
       }
      return str;
 }

 var getAllKey = function() {
      var str="";

      for (var i = 0; i < this.arr.length; i++) {
             str += this.arr[i].key+";";
       }
      return str;
 }

 var remove = function(key) {
  var v;
  for (var i = 0; i < this.arr.length; i++) {
   v = this.arr.pop();
   if ( v.key === key ) {
    continue;
   }
   this.arr.unshift(v);
  }
 }
  this.arr_All = function(_index) {
        if (_index < 0 || _index >= this.arr.length) {
            return null;
        }
        return this.arr[_index];
    };
 var size = function() {
  return this.arr.length;
 }

 var isEmpty = function() {
  return this.arr.length <= 0;
 }
}