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JavaScript JavaScript and the DOM (Retiring) Making Changes to the DOM Removing an Element from the DOM

Posted by Kathryn Notson
Kathryn Notson
25,941 Points

JavaScript and the DOM > Making Changes to the DOM > Removing an Element from the DOM

"3. Remove the list item element stored in firstListItem from the DOM."

I've tried various ways to do the first 2 code challenge questions, but still not able to get the 3rd question.

1st question could be: a. let myList = document.querySelector('ul'); b. let myList = document.getElementByTagName('ul')[0];

2nd question could be: a. let firstListItem = document.getElementById('first'); or b. document.querySelector('li:first-child');

3rd question: ul.removeChild(firstListItem); doesn't work. I get an error message telling me that Task 1 is no longer passing. I tried myList.removeChild(firstListItem); & that didn't work either.

Aha! I figured it out on my own. Hint: use the same type of query for the first 2 questions where you get the first item of the collection.

index.html 
<!DOCTYPE html>
<html>
    <head>
        <title>DOM Manipulation</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <ul>
            <li id="first">First Item</li>
            <li id="second">Second Item</li>
            <li id="third">Third Item</li>
        </ul>
        <script src="app.js"></script>
    </body>
</html>
app.js 
let myList = document.getElementByTagName('ul')[0];
let firstListItem = document.querySelector('li:first-child');
myList.removeChild(firstListItem);

2 Answers

Kathryn Notson
Kathryn Notson
25,941 Points
Kathryn Notson
Kathryn Notson
25,941 Points

Steven Parker:

Yes, syntax is very strict. You can create interesting errors with punctuation marks used as syntax or not camelCasing variables. Some of them would create a funny video show. :-)

Steven Parker
Steven Parker
231,248 Points
Steven Parker
Steven Parker
231,248 Points

It looks like you had a typo.

On your first try, you spelled "mylist" (with a lower-case "l") instead of "myList" (with captal "L") on the third line. Applying a method to an undefined variable invalidated the whole script, and it always re-tests task 1 first.

Any method that produces the correct result for tasks 1 and 2 is fine for task 3.

Kathryn Notson
Kathryn Notson
25,941 Points

Steven Parker:

I didn't mean to mistype "myList". I played with the 1st two questions several times, & yes, the code challenge will tell you that more than 1 option is correct for them. It's whether the 1st Task still passes or not when you answer the 3rd question. That's the problem I had.

Steven Parker
Steven Parker
231,248 Points
Steven Parker
Steven Parker
231,248 Points

I understand. And it was the error on the third line that caused you to get that message. Anytime you introduce a syntax error it makes the previous tasks appear to be invalid to the checker, even if you made no changes to the code done for those tasks.