Bubble Sort Algorithm in Java

Here's a Java implementation of the Bubble Sort algorithm:

public class BubbleSortExample {
    public static void main(String[] args) {
        int[] array = {5, 3, 8, 6, 2};

        System.out.println("Original Array:");
        printArray(array);

        bubbleSort(array);

        System.out.println("Sorted Array:");
        printArray(array);
    }

    // Bubble Sort Method
    public static void bubbleSort(int[] arr) {
        int n = arr.length;
        boolean swapped;

        // Outer loop for each pass
        for (int i = 0; i < n - 1; i++) {
            swapped = false;

            // Inner loop for comparing adjacent elements
            for (int j = 0; j < n - 1 - i; j++) {
                if (arr[j] > arr[j + 1]) {
                    // Swap elements if they are in the wrong order
                    int temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;

                    swapped = true;
                }
            }

            // If no swaps were made during a pass, the array is sorted
            if (!swapped) {
                break;
            }
        }
    }

    // Helper method to print the array
    public static void printArray(int[] arr) {
        for (int num : arr) {
            System.out.print(num + " ");
        }
        System.out.println();
    }
}
    

Explanation

1. Main Method:
   • Initializes an array: {5, 3, 8, 6, 2}.
   • Calls the bubbleSort method to sort the array.
   • Prints the array before and after sorting using the printArray method.
2. Bubble Sort Method:
   • Loops through the array, comparing adjacent elements.
   • Swaps elements if they are out of order.
   • Tracks if any swaps were made using a boolean swapped.
   • Breaks out of the loop early if the array is already sorted (optimization).
3. Print Array Method:
   • A simple utility to print the array elements.

Output

When you run the program, the output will be:

Original Array:
    5 3 8 6 2 
Sorted Array:
    2 3 5 6 8    
    

This implementation includes an optimization to stop the algorithm early if no swaps occur during a pass.