How to check if a random generated number is repeated from a button click? JavaScript

Question

This is my code so far. It's basically a randomizer based on images. I got the random pictures to change, but I realized that the images repeat if the generated number is repeated again from the button clicked. Is there a way I can display that message? Like the number has been repeated again. Sorry, I'm still a javascript newbie.

btnRandom.addEventListener('click', function () {
    const numRandom = Math.trunc(Math.random() * 9);
    console.log(numRandom);

    characterEl.src = `img/genshin_characters/card-${numRandom}.webp`;

    if (numRandom) {
        console.log('you got the same character again!');
    }
});

Answer 1

I assume you don't want to random same number twice in a row. So use a variable to remember the last one.

var last
btnRandom.addEventListener('click', function() {
  var numRandom
  while ((numRandom = Math.trunc(Math.random() * 9)) === last) {
    console.log("will randomize again");
  }
  console.log(numRandom)
  // characterEl.src = `img/genshin_characters/card-${numRandom}.webp`;
  last = numRandom
});

<button id="btnRandom">btnRandom</button>