Copy an array

CopyArray.java

package interviews;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class CopyArray {

    public static void main(String args[]) {

        int[] a1 = {1, 2, 3};
        int[] a2 = {4, 5, 6};
        int[] a3 = new int[a1.length + a2.length];

        System.arraycopy(a1, 0, a3, 0, a1.length);
        System.arraycopy(a2, 0, a3, a1.length, a2.length);
        System.out.println(Arrays.toString(a3));


        String[] s1 = {"aa", "bb"};
        String[] s2 = {"cc", "ee"};
        List<String> s3 = new ArrayList<>(s1.length + s2.length);

        Collections.addAll(s3, s1);
        Collections.addAll(s3, s2);

        System.out.println(s3);
    }
}