You can add an event listener to all the elements returned by a document.querySelectorAll() call by iterating over those results using the for..of loop:

const buttons = document.querySelectorAll("#select .button")
for (const button of buttons) {
  button.addEventListener('click', function(event) {

It’s important to note that document.querySelectorAll() does not return an array, but a NodeList object.

You can iterate it with forEach or for..of, or you can transform it to an array with Array.from() if you want.

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