how the insertion sort work code example

Example 1: program for insertion sort

# another method similar to insertion sort

def insertionSort(arr):
    for i in range(1, len(arr)):
        k = i
        for j in range(i-1, -1, -1):
            if arr[k] < arr[j]:  # if the key element is smaller than elements before it
                temp = arr[k]  # swapping the two numbers
                arr[k] = arr[j]
                arr[j] = temp

                k = j  # assigning the current index of key value to k
        

arr = [5, 2, 9, 1, 10, 19, 12, 11, 18, 13, 23, 20, 27, 28, 24, -2]

print("original array \n", arr)
insertionSort(arr)
print("\nSorted array \n", arr)

Example 2: insertion sort

// Por ter uma complexidade alta,
// não é recomendado para um conjunto de dados muito grande.
// Complexidade: O(n²) / O(n**2) / O(n^2)
// @see https://www.youtube.com/watch?v=TZRWRjq2CAg
// @see https://www.cs.usfca.edu/~galles/visualization/ComparisonSort.html

function insertionSort(vetor) {
    let current;
    for (let i = 1; i < vetor.length; i += 1) {
        let j = i - 1;
        current = vetor[i];
        while (j >= 0 && current < vetor[j]) {
            vetor[j + 1] = vetor[j];
            j--;
        }
        vetor[j + 1] = current;
    }
    return vetor;
}

insertionSort([1, 2, 5, 8, 3, 4])