How to pass a parameter in JavaScript function from HTML?

To pass a parameter in JavaScript function from HTML, add it in the onclick attribute like so: onclick="myFunction('parameter')".

For example, you can pass Hello World! string to myFunction in onclick listener of a button like so:

<script>
  function myFunction(text) {
    alert(text);
  }
</script>
<button onclick="myFunction('Hello World!')">I am a button!</button>