112-use-recursion-to-create-countdown.js

/*
Use Recursion to Create a Countdown:
We have defined a function called countdown with one parameter (n).
The function should use recursion to return an array containing the integers n through 1 based on the n parameter.
If the function is called with a number less than 1, the function should return an empty array.
For example, calling this function with n = 5 should return the array [5, 4, 3, 2, 1].
Your function must use recursion by calling itself and must not use loops of any kind.

- countdown(-1) should return an empty array.
- countdown(10) should return [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
- countdown(5) should return [5, 4, 3, 2, 1]
- Your code should not rely on any kind of loops (for, while or higher order functions such as forEach, map, filter, and reduce).
- You should use recursion to solve this problem.
 */
// Only changed code below this line
function countdown(n){
    if (n < 1) {
        return [];
    } else {
        const countArray = countdown(n - 1);
        countArray.unshift(n);
        return countArray;
    }
}
// Only changed code above this line