JavaScript中实现map功能代码分享

/*  * MAP对象，实现MAP功能  *  * 接口：  * size()     获取MAP元素个数  * isEmpty()    判断MAP是否为空  * clear()     删除MAP所有元素  * put(key, value)   向MAP中增加元素（key, value)   * remove(key)    删除指定KEY的元素，成功返回True，失败返回False  * get(key)    获取指定KEY的元素值VALUE，失败返回NULL  * element(index)   获取指定索引的元素（使用element.key，element.value获取KEY和VALUE），失败返回NULL  * containsKey(key)  判断MAP中是否含有指定KEY的元素  * containsValue(value) 判断MAP中是否含有指定VALUE的元素  * values()    获取MAP中所有VALUE的数组（ARRAY）  * keys()     获取MAP中所有KEY的数组（ARRAY）  *  * 例子：  * var map = new Map();  *  * map.put("key", "value");  * var val = map.get("key")  * ……  *  */  function Map() {      this.elements = new Array();            //获取MAP元素个数      this.size = function() {          return this.elements.length;      }            //判断MAP是否为空      this.isEmpty = function() {          return(this.elements.length < 1);      }            //删除MAP所有元素      this.clear = function() {          this.elements = new Array();      }            //向MAP中增加元素（key, value)       this.put = function(_key, _value) {          this.elements.push( {              key : _key,              value : _value          });      }            //删除指定KEY的元素，成功返回True，失败返回False      this.remove = function(_key) {          var bln = false;          try{              for(i = 0; i < this.elements.length; i++) {                  if(this.elements[i].key == _key) {                      this.elements.splice(i, 1);                      return true;                  }              }          } catch(e) {              bln = false;          }          return bln;      }            //获取指定KEY的元素值VALUE，失败返回NULL      this.get = function(_key) {          try{              for(i = 0; i < this.elements.length; i++) {                  if(this.elements[i].key == _key) {                      return this.elements[i].value;                  }              }          } catch(e) {              return null;          }      }            //获取指定索引的元素（使用element.key，element.value获取KEY和VALUE），失败返回NULL      this.element = function(_index) {          if(_index < 0 || _index >= this.elements.length) {              return null;          }          return this.elements[_index];      }            //判断MAP中是否含有指定KEY的元素      this.containsKey = function(_key) {          varbln = false;          try{              for(i = 0; i < this.elements.length; i++) {                  if(this.elements[i].key == _key) {                      bln = true;                  }              }          } catch(e) {              bln = false;          }          return bln;      }            //判断MAP中是否含有指定VALUE的元素      this.containsValue = function(_value) {          var bln = false;          try{              for(i = 0; i < this.elements.length; i++) {                  if(this.elements[i].value == _value) {                      bln = true;                  }              }          } catch(e) {              bln = false;          }          return bln;      }            //获取MAP中所有VALUE的数组（ARRAY）      this.values = function() {          var arr = new Array();          for(i = 0; i < this.elements.length; i++) {              arr.push(this.elements[i].value);          }          return arr;      }            //获取MAP中所有KEY的数组（ARRAY）      this.keys = function() {          var arr = new Array();          for(i = 0; i < this.elements.length; i++) {              arr.push(this.elements[i].key);          }          return arr;      }  }