Java ConcurrentHashMap remove() Method

The remove() method of ConcurrentHashMap class removes the key (and its corresponding value) from this map. This method does nothing if the key is not on the map.

Syntax

public V remove(Object key)

public boolean remove(Object key, Object value)

Parameter

key - the key that needs to be removed

value - value expected to be associated with the specified key

Returns

the previous value associated with key, or null if there was no mapping for key

Throw

NullPointerException.

Example 1

import java.util.concurrent.*; 

import java.util.*; 
  
public class  ConcurrentHashMapremoveExample1 { 
  
    public static void main(String[] args) 
    { 
          // crete a HashMap and add some values 
        HashMap<String, Integer> mapcon 
            = new HashMap<>(); 
        mapcon.put("k1", 100); 
        mapcon.put("k2", 200); 
        mapcon.put("k3", 300); 
        mapcon.put("k4", 400); 
        System.out.println("HashMap values :\n " + mapcon.toString());  
        mapcon.remove("k2");
        System.out.println("New HashMap after remove :\n "+ mapcon); 
    } 
} 

Test it Now

Output:

HashMap values :
 {k1=100, k2=200, k3=300, k4=400}
New HashMap after remove :
 {k1=100, k3=300, k4=400}

Example 2

import java.util.concurrent.*; 
  
import java.util.*; 
  
public class  ConcurrentHashMapremoveExample2 { 
  
    public static void main(String[] args) 
    { 
          // crete a HashMap and add some values 
        HashMap<String, Integer> mapcon 
            = new HashMap<>(); 
        mapcon.put("k1", 100); 
        mapcon.put("k2", 200); 
        mapcon.put("k3", 300); 
        mapcon.put("k4", 400); 
        System.out.println("HashMap values :\n " + mapcon.toString());  
        //passing key along with value
        mapcon.remove("k2",200);
        System.out.println("New HashMap after remove :\n "+ mapcon); 
    } 
}

Test it Now

Output:

HashMap values :
 {k1=100, k2=200, k3=300, k4=400}
New HashMap after remove :
 {k1=100, k3=300, k4=400}

Next TopicJava ConcurrentHashMap

← prev next →

For Videos Join Our Youtube Channel: Join Now

Feedback

Send your Feedback to [email protected]

Help Others, Please Share

Learn Latest Tutorials

Splunk

SPSS

Swagger

Transact-SQL

Tumblr

ReactJS

Regex

Reinforcement Learning

R Programming

RxJS

React Native

Python Design Patterns

Python Pillow

Python Turtle

Keras

Preparation

Aptitude

Reasoning

Verbal Ability

Interview Questions

Company Questions

Trending Technologies

Artificial Intelligence

AWS

Selenium

Cloud Computing

Hadoop

ReactJS

Data Science

Angular 7

Blockchain

Git

Machine Learning

DevOps

B.Tech / MCA

DBMS

Data Structures

DAA

Operating System

Computer Network

Compiler Design

Computer Organization

Discrete Mathematics

Ethical Hacking

Computer Graphics

Software Engineering

Web Technology

Cyber Security

Automata

C Programming

C++

Java

.Net

Python

Programs

Control System

Data Mining

Data Warehouse

^{Like/Subscribe us for latest updates or newsletter}