HashMap Code implemented by javascript

Copy codeThe Code is as follows:
<Script language = "javascript">
Function HashMap (){
/** Map size **/
Var size = 0;
/** Object **/
Var entry = new Object ();
/** Map storage put method **/
This. put = function (key, value ){
If (! This. containsKey (key )){
Size ++;
Entry [key] = value;
}
}
/** Map get method **/
This. get = function (key ){
Return this. containsKey (key )? Entry [key]: null;
}
/** Map remove Method **/
This. remove = function (key ){
If (this. containsKey (key) & (delete entry [key]) {
Size --;
}
}
/** Include Key **/
This. containsKey = function (key ){
Return (key in entry );
}
/** Include Value **/
This. containsValue = function (value ){
For (var prop in entry ){
If (entry [prop] = value ){
Return true;
}
}
Return false;
}
/** All values **/
This. values = function (){
Var values = new Array ();
For (var prop in entry ){
Values. push (entry [prop]);
}
Return values;
}
/** All keys **/
This. keys = function (){
Var keys = new Array ();
For (var prop in entry ){
Keys. push (prop );
}
Return keys;
}
/** Map size **/
This. size = function (){
Return size;
}
/** Clear Map **/
This. clear = function (){
Size = 0;
Entry = new Object ();
}

}
// Create a HashMap object
Var hashMap = new HashMap ();
HashMap. put ("A", "1 ");
HashMap. put ("B", "2 ");
HashMap. put ("A", "5 ");
HashMap. put ("C", "3 ");
HashMap. put ("A", "4 ");
Alert (hashMap. size ());

</Script>