 <p>You cannot perform append operation on array. Try the following. </p> <p><code>String[] list = new String[6];</code><br> <code>list[0] = "One";</code><br> <code>list[1] = "Two";</code><br> <code>list[2] = "Three";</code><br> <code>list[3] = "Four";</code><br> <code>list[4] = "Five";</code><br> <code>list[5] = "Six";</code><br> <code>String[] list2 = new String[list.length / 2];</code><br> <code>for (int i = 0, j = 0; i &lt; list.length; i++, j++)</code><br> <code>{</code><br> <code>list2[j] = list[i] + list[++i];</code><br> <code>}</code> </p>