Different ways of Sorting using built in functions-Java Programming

     Sorting is a process of arranging elements in particular order. It may be ascending and descending order.

Here, two examples are given to sort the elements using built in functions.

• ·       Arrays.sort()
• ·       Custom comparators

Java Program to sort integers using ‘Arrays.sort()’:

              This program reads the integer array from user. It process it using ‘Arrays.sort()’ function.

Finally, it prints the sorted integers.

Program:

   import java.util.Arrays;

   import java.util.Collections;

   import java.util.Scanner;

   public class SortEg1 {

       public static void main(String[] args) {

          Scanner scanner = new Scanner(System.in);

          System.out.print("Enter number of elements: ");

          int no = scanner.nextInt();

          int[] integerArray = new int[no];

          for (int i = 0; i < no; i++)

          {

           System.out.print("Enter element: ");

           integerArray[i] = scanner.nextInt();

          }

           Arrays.sort(integerArray);

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

       }

   }

Output:

C:\raji\blog>javac SortEg1.java

C:\raji\blog>java SortEg1

Enter number of elements: 5

Enter element: 45

Enter element: 56

Enter element: 9

Enter element: 23

Enter element: 34

[9, 23, 34, 45, 56]

This is a normal sorting.

If you want to sort the data in reverse manner, let us use the custom comparators.

Java Program to sort the string elements in reverse order:

              This program reads the number of String elements and input strings from the user. Using the custom comparator, it sorts in reverse order.

At last, it prints the data.

Program:

   import java.util.Arrays;

   import java.util.Comparator;

   import java.util.Scanner;

   public class CustomSortEg {

       public static void main(String[] args) {

          Scanner scanner = new Scanner(System.in);

          System.out.print("Enter number of Strings: ");

          int no = scanner.nextInt();

          String[] a = new String[no];

          for (int i = 0; i < no; i++)

          {

           System.out.print("Enter element: ");

           a[i] = scanner.next();

          }

           Arrays.sort(a, Comparator.reverseOrder());

           System.out.println("Sorting in reverse order");

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

       }

   }

Output:

C:\raji\blog>javac CustomSortEg.java

C:\raji\blog>java CustomSortEg

Enter number of Strings: 5

Enter element: car

Enter element: van

Enter element: bike

Enter element: truck

Enter element: bus

Sorting in reverse order

[van, truck, car, bus, bike]

That’s all. These are the ways to sort the elements using built in functions.