JavaScript Mapの簡単な例(共有)

jsでMapを書いて、機能を遍歴しています.コメントしてください.
//map.js

Array.prototype.remove = function(s) { 
  for (var i = 0; i < this.length; i++) { 
    if (s == this[i]) 
      this.splice(i, 1); 
  } 
} 
 
/** 
 * Simple Map 
 * 
 * 
 * var m = new Map(); 
 * m.put('key','value'); 
 * ... 
 * var s = ""; 
 * m.each(function(key,value,index){ 
 *   s += index+":"+ key+"="+value+"
"; 
 * }); 
 * alert(s); 
 * 
 * @author dewitt 
 * @date 2008-05-24 
 */
function Map() { 
  /**       (    ) */
  this.keys = new Array(); 
  /**      */
  this.data = new Object(); 
   
  /** 
   *         
   * @param {String} key 
   * @param {Object} value 
   */
  this.put = function(key, value) { 
    if(this.data[key] == null){ 
      this.keys.push(key); 
    } 
    this.data[key] = value; 
  }; 
   
  /** 
   *          
   * @param {String} key 
   * @return {Object} value 
   */
  this.get = function(key) { 
    return this.data[key]; 
  }; 
   
  /** 
   *         
   * @param {String} key 
   */
  this.remove = function(key) { 
    this.keys.remove(key); 
    this.data[key] = null; 
  }; 
   
  /** 
   *   Map,       
   * 
   * @param {Function}      function(key,value,index){..} 
   */
  this.each = function(fn){ 
    if(typeof fn != 'function'){ 
      return; 
    } 
    var len = this.keys.length; 
    for(var i=0;i