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Java Program to Implement Bubble Sort algorithm

Java Program to Implement Bubble Sort algorithm

In this example, we will learn to execute bubble sort algorithm in Java.

To understand this example, you should have the knowledge of the following Java programming topics:


Example: Java Program to Implement Bubble Sort Algorithm

// import the Class
import java.util.Arrays;
import java.util.Scanner;

class Main {

  // create an object of scanner
  // to take input from the user
  Scanner input = new Scanner(System.in);

  // method to perform bubble sort
  void bubbleSort(int array[]) {
    int size = array.length;

    // for ascending or descending sort
    System.out.println("Choose Sorting Order:");
    System.out.println("1 for Ascending \n2 for Descending");
    int sortOrder = input.nextInt();

    // run loops two times
    // first loop access each element of the array
    for (int i = 0; i < size - 1; i++)

      // second loop performs the comparison in each iteration
      for (int j = 0; j < size - i - 1; j++)

        // sort the array in ascending order
        if (sortOrder == 1) {
          // compares the adjacent element
          if (array[j] > array[j + 1]) {

            // swap if left element is greater than right
            int temp = array[j];
            array[j] = array[j + 1];
            array[j + 1] = temp;
          }
        }

        // sort the array in descending order
        else {
          // compares the adjacent element
          if (array[j] < array[j + 1]) {

            // swap if left element is smaller than right
            int temp = array[j];
            array[j] = array[j + 1];
            array[j + 1] = temp;
          }
        }

  }

  // driver code
  public static void main(String args[]) {

    // create an array
    int[] data = { -2, 45, 0, 11, -9 };

    // create an object of Main class
    Main bs = new Main();

    // call the method bubbleSort using object bs
    // pass the array as the method argument
    bs.bubbleSort(data);
    System.out.println("Sorted Array in Ascending Order:");

    // call toString() of Arrays class
    // to convert data into the string
    System.out.println(Arrays.toString(data));
  }
}

Output 1

Choose Sorting Order:
1 for Ascending 
2 for Descending
1
Sorted Array:
[-9, -2, 0, 11, 45]

In this case, we have entered 1 as input. Hence, the program sort the array in ascending order.

Output 2

Choose Sorting Order:
1 for Ascending
2 for Descending
2
Sorted Array:
[45, 11, 0, -2, -9]

In this case, we have entered 2 as input. Hence, the program sort the array in descending order.

If you want to learn more about the bubble sort algorithm, visit Bubble Sort Algorithm.

Note: We have used the Java Scanner Class to take input from the user.