If you have two or more Map collections in Java and you want to add them, make use of there putAll method.
Example:package org.code2care.java.collection.examples;
import java.util.HashMap;
import java.util.Map;
/**
* Example: Add two Maps
*
* Author: Code2care.org
* Date: 3nd May 2023
* Version: v1.0
*
*/
public class CombineMapsJava {
public static void main(String[] args) {
Map<String, Integer> countriesMap1 = new HashMap<>();
countriesMap1.put("China", 1);
countriesMap1.put("Japan", 2);
Map<String, Integer> countriesMap2 = new HashMap<>();
countriesMap2.put("Canada", 3);
countriesMap2.put("USA", 4);
Map<String, Integer> countriesMap = new HashMap<>();
countriesMap.putAll(countriesMap1);
countriesMap.putAll(countriesMap2);
System.out.println(countriesMap);
}
}
Output:
Facing issues? Have Questions? Post them here! I am happy to answer!
Author Info:
Rakesh (He/Him) has over 14+ years of experience in Web and Application development. He is the author of insightful How-To articles for Code2care.
Follow him on: X
You can also reach out to him via e-mail: rakesh@code2care.org
More Posts related to Java,
- Get the current timestamp in Java
- Java Stream with Multiple Filters Example
- Java SE JDBC with Prepared Statement Parameterized Select Example
- Fix: UnsupportedClassVersionError: Unsupported major.minor version 63.0
- [Fix] Java Exception with Lambda - Cannot invoke because object is null
- 7 deadly java.lang.OutOfMemoryError in Java Programming
- How to Calculate the SHA Hash Value of a File in Java
- Java JDBC Connection with Database using SSL (https) URL
- How to Add/Subtract Days to the Current Date in Java
- Create Nested Directories using Java Code
- Spring Boot: JDBCTemplate BatchUpdate Update Query Example
- What is CA FE BA BE 00 00 00 3D in Java Class Bytecode
- Save Java Object as JSON file using Jackson Library
- Adding Custom ASCII Text Banner in Spring Boot Application
- [Fix] Java: Type argument cannot be of primitive type generics
- List of New Features in Java 11 (JEPs)
- Java: How to Add two Maps with example
- Java JDBC Transition Management using PreparedStatement Examples
- Understanding and Handling NullPointerException in Java: Tips and Tricks for Effective Debugging
- Steps of working with Stored Procedures using JDBCTemplate Spring Boot
- Java 8 java.util.Function and BiFunction Examples
- The Motivation Behind Generics in Java Programming
- Get Current Local Date and Time using Java 8 DateTime API
- Java: Convert Char to ASCII
- Deep Dive: Why avoid java.util.Date and Calendar Classes
More Posts:
- Where does brew install python in macOS - Python
- How to migrate Kaizala to Microsoft Teams - Teams
- Rust: Write and Run Hello World! Program Example - Rust
- Change Android EditText Cursor Height - Android
- The author stylesheet specified in tag script is too long - document contains 21759 bytes whereas the limit is 10000 bytes - Html
- Change Line Endings (Encoding Windows/Mac/Unix CR/LF/CRLF) Sublime Text - Sublime-Text
- Error: Safari quit unexpectedly. Problem Report for Safari - MacOS
- How to Change Bluetooth Name of your iPhone - iOS