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

Phaedra Ford
Phaedra Ford
2,643 Points

How do I "Add a condition that changes the background of the <input> elements only." ?

Hello!

I've hit a bit of a roadblock working on this challenge and I'm not sure what I'm doing wrong/right. I selected the 'input' tag with document.getElementsByTagName and set it equal to a variable, input. Then in my event handler I added a for loop to iterate through the input elements and change their background to black.

If anyone could give me some pointers I'd really appreciate it!

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

section.addEventListener('click', (e) => {
  e.target.style.backgroundColor = 'rgb(255, 255, 0)';
  for ( let i = 0; i < input.length; i++; ) { 
    input[i].style.backgroundColor = 'black';
  }
});
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>
HIDAYATULLAH ARGHANDABI
HIDAYATULLAH ARGHANDABI
21,058 Points

Hello Phaedra Ford, Actually you have done a great job you should repeat the same for the input as repeated for section[0]

3 Answers

Hey Phaedra Ford,

For this challenge, you can use the if statement and only target the Input element rather than selecting its all child elements.

Here's how you can achieve that:

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

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

Hope this helps!

Phaedra Ford
Phaedra Ford
2,643 Points

Thank you so much for your help! The solution makes total sense. I think I also encountered an error because I used the color 'black' instead of the pre-chosen rgb color value - silly me.

I am a bit confused with some of the smaller details on this course, namely the following: When I coded along (In Visual Studio Code), I didn't notice that my solution ended up being written as;

taskList.addEventListener("mouseover", (event) => {
    if (event.target.tagName = 'LI'){
        event.target.textContent = event.target.textContent.toUpperCase();
    }
});

Which worked just fine - notice the 'not strict equal' and 'apostrophes'? I don't quite get what the actual differences are here, compared to your example of 'strict equal' and 'quotation marks'. I understand why the challenge cannot check for every strange mutation of the code writing, but I would love to know the actual difference it makes.

Hey Phaedra Ford,

I am glad that you managed to fix it yourself, that's the part of learning.

Happy Coding!

HIDAYATULLAH ARGHANDABI
HIDAYATULLAH ARGHANDABI
21,058 Points

Hello Phaedra Ford, Actually you have done a great job you should repeat the same for the input as repeated for section[0]