Sorting with Elegance: Bubble Sort in PHP

Sorting with Elegance: Bubble Sort in PHP

Play this article


Sorting is a fundamental operation in computer science and programming. One simple yet widely used sorting algorithm is bubble sort. In this blog post, we will unravel the inner workings of bubble sort and walk through its implementation using PHP. By the end, you'll have a clear understanding of this sorting technique and how to utilize it effectively.

Understanding Bubble Sort:

Bubble sort is a comparison-based sorting algorithm that repeatedly compares adjacent elements and swaps them if they are in the wrong order. The algorithm progresses through the dataset like bubbles rising to the surface, with the largest or smallest elements "bubbling" to their correct positions in each pass. Bubble sort is easy to understand and implement, but it may not be the most efficient algorithm for large datasets.

Implementing Bubble Sort in PHP:

Let's dive into the implementation of the bubble sort algorithm using PHP. We'll start by defining a function called bubbleSort that takes in an array to sort.

function bubbleSort($array) {
    $length = count($array);

    for ($i = 0; $i < $length - 1; $i++) {
        $swapped = false;

        for ($j = 0; $j < $length - $i - 1; $j++) {
            if ($array[$j] > $array[$j + 1]) {
                // Swap the elements
                $temp = $array[$j];
                $array[$j] = $array[$j + 1];
                $array[$j + 1] = $temp;

                $swapped = true;

        // If no swaps were made in the inner loop, the array is already sorted
        if (!$swapped) {

    return $array;

Explanation of the Implementation:

  1. The bubbleSort function takes an array as input and returns the sorted array.

  2. We determine the length of the array using the count function and store it in the $length variable.

  3. We use two nested for loops to iterate through the array. The outer loop ($i) controls the number of passes, and the inner loop ($j) performs the comparisons and swaps.

  4. Inside the inner loop, we compare adjacent elements $array[$j] and $array[$j + 1]. If they are in the wrong order (the first element is greater than the second), we swap them using a temporary variable $temp.

  5. After each pass, we check if any swaps were made ($swapped flag). If no swaps occurred in a pass, it means the array is already sorted, and we break out of the outer loop.

  6. Finally, we return the sorted array.

Example Usage: Now, let's see the bubble sort algorithm in action with an example:

$data = [7, 3, 9, 2, 5];
$sortedArray = bubbleSort($data);

echo "Sorted Array: ";
foreach ($sortedArray as $element) {
    echo $element . " ";

In this example, we have an array called $data containing some integer values. We want to sort this array using the bubbleSort function. The sorted array is then displayed using a foreach loop.


Bubble sort, despite its simplicity, serves as an important foundation for understanding sorting algorithms. In this blog post, we explored the concept of bubble sort and implemented it using PHP. While bubble sort may not be the most efficient algorithm for large datasets, its simplicity and ease of implementation make it a valuable learning tool. By mastering bubble sort, you have taken a significant step toward understanding more complex sorting techniques. So go ahead, utilize bubble sort when appropriate, and let the sorting elegance unfold!