Merging two sorted arrays

public static int[] merge(int[] a, int[] b) {

    int[] answer = new int[a.length + b.length];
    int i = 0, j = 0, k = 0;
    while (i < a.length && j < b.length)
    {
        if (a[i] < b[j])
        {
            answer[k] = a[i];
            i++;
        }
        else
        {
            answer[k] = b[j];
            j++;
        }
        k++;
    }

    while (i < a.length)
    {
        answer[k] = a[i];
        i++;
        k++;
    }

    while (j < b.length)
    {
        answer[k] = b[j];
        j++;
        k++;
    }

    return answer;
}

def mergeArrays(arr1, arr2, n1, n2):
    arr3 = [None] * (n1 + n2)
    i = 0
    j = 0
    k = 0
 
    while i < n1 and j < n2:
        if arr1[i] < arr2[j]:
            arr3[k] = arr1[i]
            k = k + 1
            i = i + 1
        else:
            arr3[k] = arr2[j]
            k = k + 1
            j = j + 1
 
    while i < n1:
        arr3[k] = arr1[i]
        k = k + 1
        i = i + 1
 
    while j < n2:
        arr3[k] = arr2[j]
        k = k + 1
        j = j + 1