Implementing Bubble Sort Algorithm in Java

Bubble Sort is a simple sorting algorithm that repeatedly steps through a list, comparing adjacent elements and swapping them if they are in the wrong order.

Reason

Bubble Sort is a simple and easy to understand algorithm and is often the first sorting algorithm that students learn. Despite its simplicity, it is not the most efficient sorting algorithm and is used mostly in educational contexts.

Example Code with Output

public class BubbleSort {

  public static void main(String[] args) {
    int[] intArray = { 20, 35, -15, 7, 55, 1, -22 };

    for (
      int lastUnsortedIndex = intArray.length - 1;
      lastUnsortedIndex > 0;
      lastUnsortedIndex--
    ) {
      for (int i = 0; i < lastUnsortedIndex; i++) {
        if (intArray[i] > intArray[i + 1]) {
          swap(intArray, i, i + 1);
        }
      }
    }

    for (int i = 0; i < intArray.length; i++) {
      System.out.println(intArray[i]);
    }
  }

  public static void swap(int[] array, int i, int j) {
    if (i == j) {
      return;
    }
    int temp = array[i];
    array[i] = array[j];
    array[j] = temp;
  }
}

Output:

-22
-15
1
7
20
35
55