Javascript and jQuery Can't Detect HTML Elements

When attempting to manipulate HTML elements using Javascript and jQuery, you may encounter the frustrating issue of undefined elements. This arises when the script attempts to access elements that haven't been defined yet in the HTML document.

In the provided HTML and script, the "script.js" file is loaded before the HTML elements it's meant to interact with. This is because the script tag is located in the

Here's a simplified explanation of the sequence of events:

1. The HTML document is parsed, creating the HTML elements.
2. The script tag for jQuery is encountered and the jQuery file is loaded.
3. Parsing resumes and creates the script tag for "script.js."
4. Parsing pauses and waits for the "script.js" file to load.
5. The "script.js" file is executed, but the div element it tries to access hasn't been created yet.

To resolve this issue, there are several options:

Move the Script Block

The most straightforward solution is to move the script tag to the end of the HTML document, just before the tag. This way, all the HTML elements will be defined before the script tries to access them.

Use jQuery's Ready Function

jQuery provides a ready function that allows you to specify a callback function to be executed when the DOM is ready. This ensures that the script code runs only after the HTML elements have been defined.

Use the Defer Attribute

Another option is to add the defer attribute to the script tag. However, this attribute is not supported by all browsers and should be used with caution.

By following any of these methods, you can ensure that your Javascript and jQuery code can successfully interact with the HTML elements defined in your document.