Initial data commit

Task/Array-concatenation/Java/array-concatenation-3.java

@@ -0,0 +1,9 @@
+int[] concat(int[] arrayA, int[] arrayB) {
+    List<Integer> list = new ArrayList<>();
+    for (int value : arrayA) list.add(value);
+    for (int value : arrayB) list.add(value);
+    int[] array = new int[list.size()];
+    for (int index = 0; index < list.size(); index++)
+        array[index] = list.get(index);
+    return array;
+}