Remove key and value pair from HashMap

In the previous post, we have seen how to sort the HashMap on the basis of keys and values. In this post we will see how to remove key and value pair from HashMap.

We use the method named as ‘remove(key)‘ where we need to pass the key which needs to be removed.

Syntax:

public V remove(Object key)

Removes the mapping for the specified key from this map if present.

Example:

import java.util.HashMap;

public class HashMapEx {

	public static void  main(String[] args){
		
		HashMap<Integer,String> hm = new HashMap<Integer,String>();
		hm.put(15, "Mobile");
		hm.put(6, "TV");
		hm.put(10, "Laptop");
		hm.put(2, "Desktop");
		hm.put(1, "Tablet");
		hm.put(23, "Microphone");
		
		System.out.println("HashMap before removing : "+hm);
		Object removeElem1 = hm.remove(6);  //Remove 6 and TV
		Object removeElem2 = hm.remove(2);	//Remove 2 and Desktop
		
		System.out.println("Remove elements are "+removeElem1 +" and "+ removeElem2);
		System.out.println("HashMap after removing : "+hm);
		
	}
}

Output:

HashMap before removing : {1=Tablet, 2=Desktop, 23=Microphone, 6=TV, 10=Laptop, 15=Mobile}
Remove elements are TV and Desktop
HashMap after removing : {1=Tablet, 23=Microphone, 10=Laptop, 15=Mobile}