sort string

static String[] sort(String[] arr) {
    // with lambda
    Arrays.sort(arr, (a, b) -> a.compareTo(b));

    // without lambda
    Arrays.sort(arr, new Comparator<String>() {
        public int compare(String a, String b) {
            return a.compareTo(b);
        }
    });
    return arr;
}

public static void main(String[] args) {
    // prints [apple, banana, blue, green, yellow]
    System.out.println(Arrays.asList(sort(new String[] { "banana", "apple", "yellow", "blue", "green" })));
}