HashMap Doubt

[Vishal Hegde]

import java.util.*;

public class HashMapDemo {

  public static void main(String[] args) {

    HashMap hm = new HashMap();
    hm.put("Rohit", new Double(3434.34));
    hm.put("Mohit", new Double(123.22));
    hm.put("Ashish", new Double(1200.34));
    hm.put("Khariwal", new Double(99.34));
    hm.put("Pankaj", new Double(-19.34));
    Set set = hm.entrySet();  // here does entrySet adds all its items in a SET?

    Iterator i = set.iterator();

    while(i.hasNext()){
      Map.Entry me = (Map.Entry)i.next();           // Is Entry some static variable that adds the elements of set in a Map
      System.out.println(me.getKey() + " : " + me.getValue() );
    }

    //deposit into Rohit's Account
    double balance = ((Double)hm.get("Rohit")).doubleValue();
    hm.put("Rohit", new Double(balance + 1000));

    System.out.println("Rohit new balance : " + hm.get("Rohit"));

  }
}  

[Campbell Ritchie]

Vishal Hegde wrote: // here does entrySet adds all its items in a SET?

Not quite sure I understand your question.
The entrySet method creates a Set with all the entries in.

// Is Entry some static variable that adds the elements of set in a Map

No. It is an interface nested inside the Map interface.

Your post would be easier to understand if you wrote the questions outside the code tags.
Why have you not given the Map type parameters? It would be a lot easier to handle a Map<String, Integer>.

[Vishal Hegde]

No. It is an interface nested inside the Map interface..

Interface can be nested??

By that you mean is-a relationship ,right using extends keyword?

[Wouter Oet]

No it's just an interface defined in another interface.

// Edit: Just to clarify. My no is the answer to the question: By that you mean is-a relationship ,right using extends keyword?

[Campbell Ritchie]

Vishal Hegde wrote: . . . Interface can be nested??

Yes. Open the src.zip file in your Java™ installation folder and you can see how it is done

. . . By that you mean is-a relationship ,right using extends keyword?

No. Not at all.