javascript - Incrementing filenames

Question

What I'm trying to do is when the back or forward button is pressed it increments the status filename + or - 1. I just can't seem to get it to increment from within the function and I'm guessing it's because x is out of it's scope and I've gotta declare it as a variable or somehow return data.

<script>
    let x = 1;
    const fileString = './status' + x + '.html'
    function backBtn() {
      x++;
      document.getElementById("myFrame").src = fileString;
    }
    function forwardBtn() {
      x--;
      document.getElementById("myFrame").src = fileString;
    }
    </script>

question from:https://stackoverflow.com/questions/65940287/incrementing-filenames

Answer 1

You need to assign when the function is called. You're actually not doing with the variable x

<script>
    let x = 1;
    function getFileStr(num) {
      return './status' + num + '.html'
    }
    function backBtn() {
      document.getElementById("myFrame").src = getFileStr(++x);
    }
    function forwardBtn() {
      document.getElementById("myFrame").src = getFileStr(--x);
    }
</script>