How to run JavaScript when an element loses focus?

You can execute JavaScript when an element loses focus by attaching an event listener for the blur event to that element.

To do this, we write:

<input type="text" id="myInputField" placeholder="Type something...">

var inputField = document.getElementById('myInputField');

inputField.addEventListener('blur', function() {
  // Your JavaScript code to run when the input field loses focus
  console.log('Input field lost focus.');
  // You can add any actions you want to perform here
});

In this example, when the input field loses focus (i.e., the user clicks outside of the input field after interacting with it), the attached event listener function will be executed.

You can replace the console.log() statement with any JavaScript code you want to run when the element loses focus.