Question

How to join two ArrayList in Java

Answer 1

import java.util.ArrayList;
import java.util.Arrays;

public class MyClass {
    public static void main(String args[]) {
        ArrayList<Integer> al1 = new ArrayList<>(Arrays.asList(40, 89, 23, 99, 89)); 
        ArrayList<Integer> al2 = new ArrayList<>(Arrays.asList(7, 8, 2, 0)); 
        
        System.out.println(al1); 
        System.out.println(al2); 
        
        ArrayList<Integer> al12 = new ArrayList<Integer>();
        
        al12.addAll(al1);
        al12.addAll(al2);
        
        System.out.println(al12); 
   
    }
}
     
     
   
     
     
/*
run:
     
[40, 89, 23, 99, 89]
[7, 8, 2, 0]
[40, 89, 23, 99, 89, 7, 8, 2, 0]

*/

 

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