Home » Core Java » util » Hashtable » Remove all mappings from Hashtable example

About Ilias Tsagklis

Ilias Tsagklis
Ilias is a software developer turned online entrepreneur. He is co-founder and Executive Editor at Java Code Geeks.

Remove all mappings from Hashtable example

With this example we are going to demonstrate how to remove all mappings from a Hashtable, that means removing all key value pairs from the Hashtable. In short, to remove all mappings from a Hashtable you should:

  • Create a new Hashtable.
  • Populate the hashtable with elements, using put(K key, V value) API method of Hashtable.
  • Invoke the clear() API method of Hashtable. It removes all keys and their corresponding values from the hashtable, so that the Hashtable contains no keys.

Let’s take a look at the code snippet that follows:

package com.javacodegeeks.snippets.core;
 
import java.util.Hashtable;

public class ClearHashtable {
 
  public static void main(String[] args) {
 
    // Create a Hashtable and populate it with elements
    Hashtable hashtable = new Hashtable();
    hashtable.put("key_1","value_1");
    hashtable.put("key_2","value_2");
    hashtable.put("key_3","value_3");
 
    System.out.println("Hashtable contains : " + hashtable);

    // void clear method() removes all mappings of Hashtable class
    hashtable.clear();

    System.out.println("Hashtable contains : " + hashtable);
  }
}

Output:

Hashtable contains : {key_3=value_3, key_2=value_2, key_1=value_1}
Hashtable contains : {}

 
This was an example of how to remove all mappings from a Hashtable in Java.

(No Ratings Yet)
Start the discussion Views Tweet it!

Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!

 

1. JPA Mini Book

2. JVM Troubleshooting Guide

3. JUnit Tutorial for Unit Testing

4. Java Annotations Tutorial

5. Java Interview Questions

6. Spring Interview Questions

7. Android UI Design

 

and many more ....

 

Receive Java & Developer job alerts in your Area

 

Leave a Reply

avatar
  Subscribe  
Notify of