How can I concatenate two arrays in Java?

Question

I need to concatenate two String arrays in Java.

void f(String[] first, String[] second) {
    String[] both = ???
}

What is the easiest way to do this?

Answer 1

There are multiple ways of concatenating two arrays but since you asked the easiest one, it has to be using addAll, take a look here.

Example:

public static void main(String[] args) {

   String[] s1 = new String[]{"D", "a", "r", "t", "h" };

    String[] s2 = new String[]{"V", "a", "d", "e", "r" };

        String[] res = ArrayUtils.addAll(s1, s2);

        System.out.println(Arrays.toString(result));

      int[] in1 = new int[]{1,2,3};

        int[] in2 = new int[]{4,5,6};

        int[] result2 = ArrayUtils.addAll(in1, in2);

        System.out.println(Arrays.toString(result2));

    }

OUTPUT

[D, a, r, t, h, V, a, d, e, r]

[1, 2, 3, 4, 5, 6]

Answer 2

Try using Apache Commons Lang library i.e. ArrayUtils.addAll(T[], T...)

Are you interested to learn Java from scratch! Have a look at this video on Java:

Use like this:

String[] both = ArrayUtils.addAll(first, second);

For more information, refer to this 

http://commons.apache.org/proper/commons-lang/javadocs/api-3.1/org/apache/commons/lang3/ArrayUtils.html#addAll%28T%5B%5D,%20T...%29