Bubble Sort - Typescript

Bubble sort algorithm is simple and easy. In bubble sort every pair of adjacent value is compared and swap if the first value is greater than the second one. By this with every iteration the greatest value goes to the right side making it ascending order.

Time Complexity

Best: O(n)
Average: O(n^2)
Worst: O(n^2)

Code

const bubbleSort = (arr: number[]): number[] => {
    const len = arr.length;

    for (let i = 0; i < len; i++) {
        for (let j = 0; j < len; j++) {
            if (arr[j] > arr[j + 1]) {
                [arr[j], arr[j + 1]] = [arr[j + 1], arr[j]];
            }
        }
    }

    return arr;
}

bubbleSort([5, 3, 1, 4, 6])

Output

Output: [1, 3, 4, 5, 6]

Here how the code is working

Iteration 0 (unsorted array): [5, 3, 1, 4, 6]
Iteration 1, key is 3 (was at index 1): [5, 3, 1, 4, 6] → [3, 5, 1, 4, 6]
Iteration 2, key is 1 (was at index 2): [3, 5, 1, 4, 6] → [1, 3, 5, 4, 6]
Iteration 3, key is 4 (was at index 3): [1, 3, 5, 4, 6] → [1, 3, 4, 5, 6]
Iteration 4, key is 6 (was at index 4): [1, 3, 4, 5, 6] → [1, 3, 4, 5, 6] — because 6 was already in the right place, no changes are made