JSFiddle - React, Tailwind, and code Playground
by victorrseloy
HTML
<h1 id="duplicatedId">
my first h1
</h1>
<h1 id="duplicatedId">
my second h1
</h1>
JavaScript
alert(document.getElementById('duplicatedId').innerText)
by victorrseloy
<h1 id="duplicatedId">
my first h1
</h1>
<h1 id="duplicatedId">
my second h1
</h1>
alert(document.getElementById('duplicatedId').innerText)