一个简单的JavaScript Map实例(分享)

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+"\n"; 
 * }); 
 * alert(s); 
 * 
 * @author dewitt 
 * @date 2008-05-24 
 */
function Map() { 
  /** 存放键的数组(遍历用到) */
  this.keys = new Array(); 
  /** 存放数据 */
  this.data = new Object(); 
   
  /** 
   * 放入一个键值对 
   * @param {String} key 
   * @param {Object} value 
   */
  this.put = function(key, value) { 
    if(this.data[key] == null){ 
      this.keys.push(key); 
    } 
    this.data[key] = value; 
  }; 
   
  /** 
   * 获取某键对应的值 
   * @param {String} key 
   * @return {Object} value 
   */
  this.get = function(key) { 
    return this.data[key]; 
  }; 
   
  /** 
   * 删除一个键值对 
   * @param {String} key 
   */
  this.remove = function(key) { 
    this.keys.remove(key); 
    this.data[key] = null; 
  }; 
   
  /** 
   * 遍历Map,执行处理函数 
   * 
   * @param {Function} 回调函数 function(key,value,index){..} 
   */
  this.each = function(fn){ 
    if(typeof fn != 'function'){ 
      return; 
    } 
    var len = this.keys.length; 
    for(var i=0;i<len;i++){ 
      var k = this.keys[i]; 
      fn(k,this.data[k],i); 
    } 
  }; 
   
  /** 
   * 获取键值数组(类似Java的entrySet()) 
   * @return 键值对象{key,value}的数组 
   */
  this.entrys = function() { 
    var len = this.keys.length; 
    var entrys = new Array(len); 
    for (var i = 0; i < len; i++) { 
      entrys[i] = { 
        key : this.keys[i], 
        value : this.data[i] 
      }; 
    } 
    return entrys; 
  }; 
   
  /** 
   * 判断Map是否为空 
   */
  this.isEmpty = function() { 
    return this.keys.length == 0; 
  }; 
   
  /** 
   * 获取键值对数量 
   */
  this.size = function(){ 
    return this.keys.length; 
  }; 
   
  /** 
   * 重写toString 
   */
  this.toString = function(){ 
    var s = "{"; 
    for(var i=0;i<this.keys.length;i++,s+=','){ 
      var k = this.keys[i]; 
      s += k+"="+this.data[k]; 
    } 
    s+="}"; 
    return s; 
  }; 
} 
 
 
function testMap(){ 
  var m = new Map(); 
  m.put('key1','Comtop'); 
  m.put('key2','南方电网'); 
  m.put('key3','景新花园'); 
  alert("init:"+m); 
   
  m.put('key1','康拓普'); 
  alert("set key1:"+m); 
   
  m.remove("key2"); 
  alert("remove key2: "+m); 
   
  var s =""; 
  m.each(function(key,value,index){ 
    s += index+":"+ key+"="+value+"\n"; 
  }); 
  alert(s); 
} 
　　//testMap.htm

"javascript" src="/UploadFiles/2021-04-02/map.js">

以上这篇一个简单的JavaScript Map实例(分享)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。