w3resource

Java: Join two array lists


15. Join Two ArrayLists

Write a Java program to join two array lists.

Pictorial Presentation:

Java Collection, ArrayList Exercises: Join two array lists

Sample Solution:-

Java Code:

import java.util.ArrayList;
import java.util.Collections;
  public class Exercise15 {
  public static void main(String[] args) {
   ArrayList<String> c1= new ArrayList<String>();
          c1.add("Red");
          c1.add("Green");
          c1.add("Black");
          c1.add("White");
          c1.add("Pink");
          System.out.println("List of first array: " + c1);
          ArrayList<String> c2= new ArrayList<String>();
          c2.add("Red");
          c2.add("Green");
          c2.add("Black");
          c2.add("Pink");
          System.out.println("List of second array: " + c2);
         
      // Let join above two list
        ArrayList<String> a = new ArrayList<String>();
        a.addAll(c1);
        a.addAll(c2);
        System.out.println("New array: " + a);
        

     }
}

Sample Output:

List of first array: [Red, Green, Black, White, Pink]                  
List of second array: [Red, Green, Black, Pink]                        
New array: [Red, Green, Black, White, Pink, Red, Green, Black, Pink]

Flowchart:

Flowchart: Join two array lists.

For more Practice: Solve these Related Problems:

  • Write a Java program to join two ArrayLists using addAll() and then remove any duplicate elements from the result.
  • Write a Java program to merge two ArrayLists of different types into a single ArrayList of objects and print them.
  • Write a Java program to join two ArrayLists and then sort the merged list using a custom comparator.
  • Write a Java program to use Java streams to concatenate two ArrayLists and collect the result into a new list.

Go to:


PREV : Swap ArrayList Elements.
NEXT : Clone ArrayList.

Java Code Editor:

Contribute your code and comments through Disqus.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.