Use Recursion to Create a Countdown: why does it increase?

JavaScript
1

This is the code:

function countup(n) {
  if (n < 1) {
    return [];
  } else {
    const countArray = countup(n - 1);
    countArray.push(n);
    return countArray;
  }
}
console.log(countup(5)); // [ 1, 2, 3, 4, 5 ]

Lesson: this seems counterintuitive since the value of n decreases , but the values in the final array are increasing . This happens because the push happens last, after the recursive call has returned. At the point where n is pushed into the array, countup(n - 1) has already been evaluated and returned [1, 2, ..., n - 1] . QUESTION: I don’t get it why does it increase? could someone give me another example? it decreases, because n-1!

2

because when it is in
const count Array = count up (n - 1);
re-enter the countup (n) function and do not go to the next line of code that would be countArray.push (n); until it find
if (n <1) { return ;}
and returns with the last one Array = count up (n - 1) with which he stayed.


function countup(5) {
  if (n < 1) {
    return [];
  } else {
    const countArray = countup(n - 1);//[1,2,3,4]
    countArray.push(n);//[1,2,3,4,5]
    return countArray;
  }
}

function countup(4) {
  if (n < 1) {
    return [];
  } else {
    const countArray = countup(n - 1);//[1,2,3]
    countArray.push(n);//[1,2,3,4]
    return countArray;
  }
}

function countup(3) {
  if (n < 1) {
    return [];
  } else {
    const countArray = countup(n - 1);//[1,2]
    countArray.push(n);//[1,2,3]
    return countArray;
  }
}

function countup(2) {
  if (n < 1) {
    return [];
  } else {
    const countArray = countup(n - 1);//[1]
    countArray.push(n);//[1,2]
    return countArray;
  }
}


function countup(1) {
  if (n < 1) {
    return [];
  } else {
    const countArray = countup(n - 1);//[]
    countArray.push(n);//[1]
    return countArray;
  }
}

function countup(0) {
  if (n < 1) {
    return [];// return []
  } else {
    const countArray = countup(n - 1);
    countArray.push(n);
    return countArray;
  }
}
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