In this example we shall show you how to remove mapping from a Hashtable, that means removing a key value pair from a Hashtable. To remove mapping from a Hashtable one should perform the following steps:
- Create a new Hashtable.
- Populate the hashtable with key value pairs, using
put(K key, V value)API method of Hashtable. - Invoke the
remove(Object key) API method of Hashtable, with a key as parameter. It removes a key and its corresponding value from the hashtable,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.util.Hashtable;
public class RemoveMappingHashtable {
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);
/*
Object remove(Object key) operantion removes a key value pair from Hashtable.
It returns either the value mapped with the key previously or null if no value was mapped.
*/
Object value = hashtable.remove("key_2");
System.out.println("After removing value : " + value + " Hashtable contains : " + hashtable);
}
}
Output:
Hashtable contains : {key_3=value_3, key_2=value_2, key_1=value_1}
After removing value : value_2 Hashtable contains : {key_3=value_3, key_1=value_1}
This was an example of how to remove mapping from a Hashtable in Java.
