Remove mapping from Hashtable example – Java

In this tutorial we are gonna see how to remove a key-value mapping from Hashtable. We will be using remove(Object key) method of Hashtable class.

Example

Method used in the below program is:

public V remove(Object key): Removes the key (and its corresponding value) from this hashtable. This method does nothing if the key is not in the hashtable.

import java.util.Hashtable;

public class RemoveMappingExample {
 
 public static void main(String[] args) {
 
    // Creating a Hashtable
    Hashtable<Integer, String> hashtable = new Hashtable<Integer, String>();
 
    // Adding Key and Value pairs to Hashtable
    hashtable.put(11,"AA");
    hashtable.put(22,"BB");
    hashtable.put(33,"CC");
    hashtable.put(44,"DD");
    hashtable.put(55,"EE");
 
    //Before remove
    System.out.println("Hashtable contains:" + hashtable);
 
    // Removing key-value pairs for key 44
    Object removedValue = hashtable.remove(44);
 
    //After remove
    System.out.println("After remove:");
    System.out.println("Hashtable Key-value pairs: " + hashtable);
 }
}

Output:

Hashtable contains:{55=EE, 44=DD, 33=CC, 22=BB, 11=AA}
After remove:
Hashtable Key-value pairs: {55=EE, 33=CC, 22=BB, 11=AA}

In the above program we have provided the key 44 while calling remove(key) method so the key-value mapping corresponding to key 44 has been removed from Hashtable and the method returned the value mapped to the key 44.