how to use time intervals in the function?

Question

I want the letters 'q' to be written only once per second. But it doubles every second. How to do this with this command?

function writeNow() {
   document.write('q');
   setInterval(writeNow, 1000);
}
writeNow();

Answer 1

You can use setTimeout

   function writeNow() {
      document.write('q');
      setTimeout(writeNow, 1000);
    }
    writeNow();

Or setInterval

function writeNow() {
  document.write('q');
}
setInterval(() => {
  writeNow()
}, 1000);

Answer 2

You want to set the interval outside the function, when you call it inside the function, it will be recursive

Try

function writeNow() {
    document.write('q');
}
setInterval(writeNow, 1000);
writeNow();

And I highly recommend against document.write as it is deprecated