hasan's blog (বল্গ)

/////////////////////////////////////////////
///// Js Object //////
///////////////////////////////////////////
// Author: NHM TAnveer Hossain Khan (Hasan)
// http://hasan.we4tech.com
// mail:admin@we4tech.com

// hashmap internal data object
JsObject=function(key, value) {
this._key=key;
this._value=value;
}

// set some methods for JsObject
JsObject.prototype.getKey=function() {
return this._key;
}

// get value
JsObject.prototype.getValue=function() {
return this._value;
}

/////////////////////////////////////////////
//// Iterator ///////
///////////////////////////////////////////
JsIterator=function(array) {
// set internal array
this._array=array;

// create inernal index counter
this._counter=0;

// set _hasNext value
if(array.length>0)
this._hasNext=true;
else
this._hasNext=false;
}

// return boolean value
JsIterator.prototype.hasNext=function() {
return this._hasNext;
}

// return object in next method
JsIterator.prototype.next=function() {
if(this._array.length>this._counter) {
// get object
var rtnObj=this._array[this._counter];
// increment counter value;
this._counter++;
// check is has next true of flase
if(this._array.length>this._counter)
this._hasNext=true;
else
this._hasNext=false;

// return data
return rtnObj;
}
else {
this._hasNext=false;
}
}
// remove object
JsIterator.prototype.remove=function() {
this._array.splice(this._counter,1);
if(this._array.length > this._counter)
this._hasNext=false;

}

/////////////////////////////////////////////
//// HashMap Object ///////
///////////////////////////////////////////

// create JsHashMap class object
JsHashMap=function() {

// init. internal array
this._array=new Array();
// set internal counter value as 0
// this counter will keep track the current index
// of array
this._counter=0;
}

// create add method
// put key and value
JsHashMap.prototype.put=function(key, value) {
// add new value
var newJsObj=new JsObject(key, value);
// add in internal array
this._array[this._counter]=newJsObj;
// increment the internal index counter
this._counter++;
}

// retrive data based on iterator
JsHashMap.prototype.iterator=function() {
// create iterator
var it=new JsIterator(this._array);
// return iterator
return it;
}

// retrive data based on keyword
JsHashMap.prototype.get=function(key) {
// create iterator object
var it=this.iterator();

// iterate untile get success
while(it.hasNext()) {
// fetch object
var getObj=it.next();

// check is found or not
if(getObj.getKey()==key)
return getObj.getValue();
}
}

// remove key and object
JsHashMap.prototype.remove=function(key) {

}

//———————————-
// Usages
//———————————-
var hash=new JsHashMap();
hash.put(“key1″,”my_value1″);
hash.put(“key2″,”my_value2″);
hash.put(“key3″,”my_value3″);
hash.put(“key4″,”my_value4″);

// retrive iterator
var it=hash.iterator();

alert(“FIRST”);
/// check iterator
while(it.hasNext()) {
var getObj=it.next();
alert(getObj.getKey()+”:”+getObj.getValue());
}
alert(“SECOND”);
/// check iterator
while(it.hasNext()) {
it.remove();
}
alert(“THIRD”);
/// check iterator
while(it.hasNext()) {
var getObj=it.next();
alert(getObj.getKey()+”:”+getObj.getValue());
}
// get single object
alert(“KEY2: “+hash.get(“key2″));
alert(“KEY3: “+hash.get(“key3″));