How to loop HashMap in java

In this tutorial we will learn how to loop HashMap using following methods:

1. For loop
2. While loop + Iterator

Example:
In the below example we are iterating the HashMap using both the methods (for loop and while loop). In while loop we have used the iterator.

package beginnersbook.com;
import java.util.HashMap;
import java.util.Map;
import java.util.Iterator;
public class Details
{
    public static void main(String [] args)
    {
        HashMap<Integer, String> hmap = new HashMap<Integer, String>();
        //Adding elements to HashMap
        hmap.put(11, "AB");
        hmap.put(2, "CD");
        hmap.put(33, "EF");
        hmap.put(9, "GH");
        hmap.put(3, "IJ");

        //FOR LOOP
        System.out.println("For Loop:");
        for (Map.Entry me : hmap.entrySet()) {
          System.out.println("Key: "+me.getKey() + " & Value: " + me.getValue());
        }

        //WHILE LOOP & ITERATOR
        System.out.println("While Loop:");
        Iterator iterator = hmap.entrySet().iterator();
        while (iterator.hasNext()) {
             Map.Entry me2 = (Map.Entry) iterator.next();
          System.out.println("Key: "+me2.getKey() + " & Value: " + me2.getValue());
        } 
    }
}

Output:

For Loop:
Key: 2 & Value: CD
Key: 3 & Value: IJ
Key: 33 & Value: EF
Key: 9 & Value: GH
Key: 11 & Value: AB
While Loop:
Key: 2 & Value: CD
Key: 3 & Value: IJ
Key: 33 & Value: EF
Key: 9 & Value: GH
Key: 11 & Value: AB

References:

• Iterator javadoc
• HashMap documentation