JSFiddle - React, Tailwind, and code Playground

HTML

<audio src="1.mp3"></audio>
<audio src="2.mp3"></audio>
<audio src="3.mp3"></audio>
<audio src="X.mp3"></audio>

<button onclick="setIDs()">setIDs</button>

JavaScript

function setIDs() {
  for (var a = 0; a < $('audio').length; a++) {
      $('audio').eq(a).attr('id', a);
      console.log("ID is " + $('audio').eq(a).attr('id'))
  }
}