Which is the right way to handle a onclick event in javascript? code example

Example 1: javascript onclick button

var button = document.querySelector('button');
button.onclick = function() {
  //do stuff
}

Example 2: onclick in js

<input type="text" name="text" id="test" onmouseover="skriv('klick')">
    <input type="button" name="send" value="Skicka" id="klick" onclick="skriv('test')">
    
    
    <script src="lib/script.js"></script>


// in lib/script.js

  function skriv(name) {
    document.getElementById(name).style.backgroundColor='red';
  }