public class sort {

     public static void main(String[] args) {

         String[] arr = {"aa","bb","cc","dd"};

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

 //        sort(arr);

 //        System.out.println(Arrays.toString(arr));

         Arrays.sort(arr);

         for (String string : arr) {

             System.out.print(string);

         }

     }

     private static void sort(String[] arr) {

         for (int i = 0; i < arr.length-1; i++) {

             for (int j = i+1; j < arr.length; j++) {

                 String temp = arr[i];

                 arr[i] = arr[j];

                 arr[j] = temp;

             }

         }

     }

 }