JavaScript JavaScript and the DOM Responding to User Interaction Event Delegation

Eniola Tijani
Eniola Tijani
3,432 Points

Currently, the event listener applies a yellow background color to the section element and its child elements when click

welp!!

app.js
let section = document.getElementsByTagName('section')[0];

section.addEventListener('click', (e) => {
  if (event.target.tagName == 'SECTION') {
  event.target.style.backgroundColor = 'rgb(255, 255, 0)';
      } else if (event.target.tagName == 'INPUT') {
  event.target.style.backgroundColor = 'blue';
    }
      });

;
index.html
<!DOCTYPE html>
<html>
    <head>
        <title>JavaScript and the DOM</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <section>
            <h1>Making a Webpage Interactive</h1>
            <p>JavaScript is an exciting language that you can use to power web servers, create desktop programs, and even control robots. But JavaScript got its start in the browser way back in 1995.</p>
            <hr>
            <p>Things to Learn</p>
            <ul>
                <li>Item One: <input type="text"></li>
                <li>Item Two: <input type="text"></li>
                <li>Item Three: <input type="text"></li>
                <li>Item Four: <input type="text"></li>
            </ul>
            <button>Save</button>
        </section>
        <script src="app.js"></script>
    </body>
</html>

3 Answers

Piotr Manczak
Piotr Manczak
8,717 Points

Try this: let section = document.getElementsByTagName('section')[0];

section.addEventListener('click', (e) => {

if (e.target.tagName == 'INPUT') {

e.target.style.backgroundColor = 'rgb(255, 255, 0)';

}

});

Linas Mackonis
Linas Mackonis
6,718 Points

Hi, this should work:

let section = document.getElementsByTagName('section')[0];
let input = document.getElementsByTagName('input');

for(let i = 0; i < input.length; i += 1) {
input[i].addEventListener('click', (e) => {
  e.target.style.backgroundColor = 'rgb(255, 255, 0)';
});

}
Michael Barlow
Michael Barlow
33,639 Points

You're also referencing event from within the callback, which is (probably) undefined in that scope. You've defined the event argument as e, so use that to get a reference to the target: e.target...