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JavaScript JavaScript and the DOM (Retiring) Responding to User Interaction Event Delegation

Posted by Hanwen Zhang
Hanwen Zhang
20,084 Points

Question: When I click the event, it turns to yellow; what can I do to click again, and let it appears normal (no color)

It is not a challenging task, but thought about this question and can't think of the solution. Please help.

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

section.addEventListener('click', (e) => {
  e.target.style.backgroundColor = 'rgb(255, 255, 0)';
});
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>

1 Answer

Peter Vann
Peter Vann
36,425 Points

Hi Hanwen!

Sorry, I stepped to go to the grocery store...

Back now (obviously!?! LOL)...

You would want something like this:

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

section.addEventListener('click', (e) => {
  if (e.target.tagName == 'INPUT') { // 'INPUT must be in all caps
      if (e.target.style.backgroundColor == 'rgb(255, 255, 0)') { // if yellow
          e.target.style.backgroundColor = ''; // set bg to empty string (to default white)
      } else {
          e.target.style.backgroundColor = 'rgb(255, 255, 0)'; //set it back to yellow
      }
  } 
});

Interesting - it even passed the challenge with your additional logic!?! LOL

I hope that helps.

Stay safe and happy coding!

Hanwen Zhang
Hanwen Zhang
20,084 Points

Hi Peter,

Thank you so much!!! I was thinking so hard, and you help me solve my confusion about how to reset it. I appreciate your help!