Introduction
In this blog, I am going to explain the Bubble sort algorithm. Bubble sort is one of the most widely used sorting algorithms by the programmers worldwide. It can be applied to any collection including array, string, numbers, or characters.
Bubble sort is very frequently asked about in job interviews. So first I am going to explain the bubble sort algorithm; Then, I will be providing a C# code to execute it.
Please refer to below link for my earlier blog on Selection sort.
The algorithm
This algorithm follows the concept of iterating through the array from the first index to the last index and comparing adjacent elements and then swapping them if they appear in the wrong order. i.e. If the next element is smaller than the current element, they are swapped.
Let us understand this with the help of an example. Let us take an input array such as - 8 5 7 3 1
The sorted output for this array is - 1 3 5 7 8
Let us see the step by step execution of the Bubble sort algorithm on the input array to get the sorted output.

Iteration 1: - 8 5 7 3 1 → 5 8 7 3 1 → 5 7 8 3 1 → 5 7 3 8 1→ 5 7 3 1 8
Iteration 2: - 5 7 3 1 8 → 5 3 7 1 8→ 5 3 1 7 8
Iteration 3: - 5 3 1 7 8 → 3 5 1 7 8 → 3 1 5 7 8
Iteration 4: - 3 1 5 7 8 → 1 3 5 7 8
Iteration 5: - 1 3 5 7 8
Hence, we got the sorted array in iteration 5.
Time Complexity: - Since we need to iterate the entire array for every element, the average and the worst case complexity of bubble sort is O(n²).
Conclusion
In this tutorial, we learned about the Bubble sort algorithm and its implementation using C#.

Matt SlayPosted Sep 13, 2019, 7:08 PM
Here is the C# code contained in the zip file referenced in this article. I pasted it to a gist on GitHub: https://gist.github.com/mattslay/c8dd41f1a404518f8cef2e371d11b432
Matt SlayPosted Sep 13, 2019, 7:05 PM
Here is my example of how to do a Bubble Sort in C#. https://gist.github.com/mattslay/84895f6ff97b49275f8845812cfbe930
Hemant KumarPosted Aug 9, 2017, 5:12 AM
Good one. Thanks for clearing the concept s.