Question

What is an event delegation in Javascript?

Answer 1

Event delegation is a technique for listening to events where you delegate a parent element as the listener for all of the events that happen inside it.

For example, if you wanted to detect field changes in inside a specific form, you can use event delegation technique,

var form = document.querySelector("#registration-form");

// Listen for changes to fields inside the form
form.addEventListener(
  "input",
  function (event) {
    // Log the field that was changed
    console.log(event.target);
  },
  false
);