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Java HashMap remove() Method with Example

HashMap Class remove() method: Here, we are going to learn about the remove() method of HashMap Class with its syntax and example.
Submitted by Preeti Jain, on March 04, 2020

HashMap Class remove() method

• remove() method is available in java.util package.
• remove() method is used to remove the key-value pairs that exist in this HashMap for the given key element (key_ele).
• remove() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• remove() method does not throw an exception at the time of removing an element.

Syntax:

    public Value remove(Object key_ele);

Parameter(s):

• Object key_ele – represents the key element whose associated key-value pair is to be deleted from this HashMap.

Return value:

The return type of the method is Value, it returns the associated value for the given key element when exists otherwise it returns null.

Example:

// Java program to demonstrate the example 
// of Value remove(Object key_ele)
// method of HashMap 

import java.util.*;

public class RemoveOfHashMap {
    public static void main(String[] args) {
        // Instantiates a HashMap object
        Map < Integer, String > map = new HashMap < Integer, String > ();

        // By using put() method is to add
        // key-value pairs in a HashMap
        map.put(10, "C");
        map.put(20, "C++");
        map.put(50, "JAVA");
        map.put(40, "PHP");
        map.put(30, "SFDC");

        // Display HashMap
        System.out.println("HashMap: " + map);

        // By using remove() method is to remove 
        // the mappings exists for the given key
        // element in this HashMap
        map.remove(50);

        // Display Modified HashMap
        System.out.print("map.remove(50): " + map);
    }
}

Output

HashMap: {50=JAVA, 20=C++, 40=PHP, 10=C, 30=SFDC}
map.remove(50): {20=C++, 40=PHP, 10=C, 30=SFDC}