js封装为map对象

 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) {
 var bln = 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;
}
}