基于JavaScript的HashMap实现

[size=small]
/**
*author:yangsenc
*time:20140920
*version:V1.0.0
*/
function HashMap(){
//特殊关键字(specialKey)用来处理特殊的保留字
//这些保留字主要是Object对象中的固有属性和方法
var specialKey = [
'valueOf',
'constructor',
'toString',
'toLocaleString',
'ropertyIsEnumerable',
'hasOwnProperty',
'isprototypeOf',
'prototype'
];
//为特殊关键字提供单独存放值的空间
var speicalValue = new Array(specialKey.length);

//特殊关键字存取标记,true 表示该位已经有值
var speicalFlag = new Array(specialKey.length);

//存放普通的关键字，只需要一个普通的Object
var normalHashMap={};

//将数值插入到HashMap
this.put = function(key,value){
if(!key){
return false;
}
//处理特殊关键字
for(var i=0;i<specialKey.length;i++){
if(key==specialKey[i]){//如果关键字等于某个特殊关键字
speicalValue[i] = value;
speicalFlag[i] = true;
return true;
}
}

//处理普通关键字
normalHashMap[key] = value;
return true;
}

this.get = function(key){
if(!key){
return null;
}
//先处理特殊关键字
for(var i=0;i<specialKey.length;i++){
if(key == specialKey[i]){
if(speicalValue[i]){
return speicalValue[i];
}else{
return null;
}
}
}

if(key in normalHashMap){
return normalHashMap[key];
}else{
return null;
}
}

//清空HashMap
this.clear = function(){
speicalValue  = new Array(specialKey.length);
speicalFlag   = new Array(specialKey.length);
normalHashMap = {};
}


//判断是否包含key
this.containsKey = function(key){
//先处理特殊关键字
   for(var i=0;i<specialKey.length;i++){
   if(key == specialKey[i]){
   if(speicalFlag[i] == true){//和关键字相同并且关键字的标志位为true
   return true;
   }else{
   return false;
   }
   }
}
//处理普通关键字
if(key in normalHashMap){
return true;
}else{
return false;
}
}

//判断是否包含Value
this.containsValue = function(value){
if(!value){
return false;
}
var contains = false;
for(var i=0;i<speicalValue.length;i++){
var v = speicalValue[i];
if(v == value){
contains = true;
break;
}
}

if(contains){
return contains;
}

for(var key in normalHashMap){
var v = normalHashMap[key];
if(v == value){
contains = true
break;
}
}
return contains;
}

//返回hashMap的长度
this.size  = function(){
var size = 0;

for(var i=0;i<speicalValue.length;i++){
if(speicalFlag[i] == true ){
size++;
}
}

for(var key in normalHashMap){
size++;
}
return size;
}

//判断hashMap是否为空
this.isEmpty = function(){
return this.size() == 0 ? true:false;
}


//根据一个key删除元素
this.remove = function(key){
if(!key){
return false;
}

for(var i=0;i<specialKey.length;i++){
if(key ==specialKey[i] && speicalFlag[i] == true ){
speicalFlag[i] = null;
speicalValue[i] = null;
return true;
}else if(key ==specialKey[i] && speicalFlag[i] == false){
return false;
}
}

for(var k in normalHashMap){
if(k == key){
delete normalHashMap[k];
return true;
}
}
return false;
}



//取得Key值
this.keySet = function(){
return getStr(0);
}

//toString 方法
//{phoneNo=18510802350, userName=yangsenc}
this.toString = function(){
return getStr(1);
}

//返回类似java中Map的entrySet
//[phoneNo=18510802350, userName=yangsenc]
this.entrySet = function(){
return getStr(2);
};

//取得所有的values
this.values = function(){
return getStr(3);
}

//公共方法，用于封装返回字符串
var getStr = function(flag){
//0： 中括号 返回keys
//1: 花括号 返回keys和values组合
//2： 中括号 返回keys和values组合
//3： 中括号 返回values
var result = "";

for(var i=0;i<specialKey.length;i++){
if(speicalValue[i] && speicalFlag[i] == true ){
if(flag == 0){
result += specialKey[i]+",";
}else if(flag == 3){
result += speicalValue[i]+",";
}else{
result += specialKey[i]+"="+speicalValue[i]+",";
}
}
}

for(var key in normalHashMap){
if(flag == 0){
result += key+",";
}else if(flag == 3){
result += normalHashMap[key]+",";
}else{
result += key+"="+normalHashMap[key]+",";
}
}

result = result.substring(0,result.length-1);
if(flag==1){
result = "{"+result+"}";
}else{
result = "["+result+"]";
}
return result;
}
}
/***********************测试****************************************/

function dwn(str){
  document.write(str +"</br>");
}

var hashMap = new HashMap();
hashMap.clear();
hashMap.put('valueOf','valueOf');
hashMap.put('constructor','constructor');
hashMap.put('toString','toString');
hashMap.put('key1','12345');
hashMap.put('key2','123456');
hashMap.put('key3',1234567);
hashMap.put('key4','12345678');
hashMap.put('key4','12345678');

dwn(hashMap.size());
hashMap.remove('toString');
dwn(hashMap.keySet());
dwn(hashMap.toString());
dwn(hashMap.entrySet());
dwn(hashMap.values());[/size]