recursion 递归

//我的答案
function countdown(myArray, n){
  if(n < 0) { myArray = []; return}
  if(n == 1) {
    myArray.unshift(n);
    return;
  }else {
    countdown(myArray, n-1)
    myArray.unshift(n);
  }
}

//官方答案，இ௰இ 😭
function countdown(myArray, n){
  if(n <= 0){
    return;
  }
  else{
    myArray.push(n);
    countdown(myArray, n - 1);
  }
}

https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-javascript/use-recursion-to-create-a-countdown

https://www.freecodecamp.org/forum/t/freecodecamp-challenge-guide-use-recursion-to-create-a-countdown/305925