If you want to add an event callback but have it run only once, you can simply use the once option in the method's options object:

  document.body.addEventListener('click', () => {
    console.log('I run only once! 😇');
  }, { once: true });

This prevents the need to otherwise immediately remove the event listener after the callback first fires (which I've been guilty of!):

  document.body.addEventListener('click', cb);

  function cb() {
    console.log('Hi! 👋');
    document.body.removeEventListener('click', cb);
  }

The more you know! 🌈

Links

MDN Article on addEventListener()

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