Exercise : array simulation practice-it

Consider the following method:

public static void arrayMystery(String[] a) {
    for (int i = 0; i < a.length; i++) {
        a[i] += a[a.length - 1 - i];
    }
}

In the left-hand column below are specific lists of strings. Indicate in the right-hand column what values would be stored in the list after method mystery executes if the string list in the left-hand column is passed to it as a parameter.

{"a", "b", "c"}
{"ac", "bb" ,"cac"}
{"a", "bb", "c", "dd"}
{"add", "bbc", "cbbc", "ddadd"}
{"z", "y", "142", "w", "xx"}
{"zxx", "yw", "142142", "wyw", "xxzxx"}