Error: The property 'classList' of null is unreachable for HTMLImageElement

Question

Error: The property 'classList' of null is unreachable for HTMLImageElement

I'm facing an issue on my website that's causing the following error message to pop up:

Uncaught TypeError: Cannot read property 'classList' of null at HTMLImageElement.

Here's the code I've been using:

https://jsfiddle.net/kikiZ/59ej2g8m/

Despite searching on other websites, I haven't been able to find a suitable solution for this problem.

The issue seems to be related to this portion of the code:

        <script>

        var menu = document.getElementById('menu');
        var nav = document.getElementById('nav');
        var exit = document.getElementById('exit');

        menu.addEventListener('click', function(e) {
            nav.classList.toggle('hide-mobile');
            e.preventDefault();
        });

    </script>

javascript html css

Answer 1

Answer №1

Fixing the toggle button for small screens

Here is the solution: Replace your JavaScript code with the following code snippet and ensure to understand it:

var menu = document.getElementById('menu');
var nav = document.querySelector('nav ul');
var exit = document.getElementById('exit');

menu.addEventListener('click', function(e) {
    nav.classList.toggle('hide-mobile');
    e.preventDefault();
});

Explanation:

FIRST:

If you intend to use the classList method, ensure that there is a class specified in the HTML within the <nav> tag. The issue arises when you are trying to search for a class within nothing, because getElementById('') searches within the DOM (the HTML file) for an Id that matches the provided argument; in your case: getElementById('nav') : it looks for an #Id named nav which does not exist. You have two options: either use getElementById('') but add an id 'nav' to your <nav> tag; like <nav id="nav">.

or opt for document.querySelector('nav') instead of document.getElementById('nav').

SECOND

After resolving the first issue, you might encounter another one where the toggle button for small screens doesn't work. This is because you are toggling the "hide-mobile" class on the <nav> element, when you should be toggling it on the <ul> element that initially contains the "hide-mobile" class.

Answer 2

Fixing the toggle button for small screens

Here is the solution: Replace your JavaScript code with the following code snippet and ensure to understand it:

var menu = document.getElementById('menu');
var nav = document.querySelector('nav ul');
var exit = document.getElementById('exit');

menu.addEventListener('click', function(e) {
    nav.classList.toggle('hide-mobile');
    e.preventDefault();
});

Explanation:

FIRST:

If you intend to use the classList method, ensure that there is a class specified in the HTML within the <nav> tag. The issue arises when you are trying to search for a class within nothing, because getElementById('') searches within the DOM (the HTML file) for an Id that matches the provided argument; in your case: getElementById('nav') : it looks for an #Id named nav which does not exist. You have two options: either use getElementById('') but add an id 'nav' to your <nav> tag; like <nav id="nav">.

or opt for document.querySelector('nav') instead of document.getElementById('nav').

SECOND

After resolving the first issue, you might encounter another one where the toggle button for small screens doesn't work. This is because you are toggling the "hide-mobile" class on the <nav> element, when you should be toggling it on the <ul> element that initially contains the "hide-mobile" class.

Answer 3

Answer №2

There are no elements in your document with the id "nav".

To fix this issue, you can either change document.getElementById('nav') to document.querySelector('nav') or add the id "nav" to the element itself.

Answer 4

There are no elements in your document with the id "nav".

To fix this issue, you can either change document.getElementById('nav') to document.querySelector('nav') or add the id "nav" to the element itself.

Error: The property 'classList' of null is unreachable for HTMLImageElement

Answer №1

Answer №2

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