Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript and the DOM (Retiring) Traversing the DOM Using previousElementSibling and insertBefore

Jinjia Lin
Jinjia Lin
11,942 Points
Posted by Jinjia Lin
Jinjia Lin
11,942 Points

Why is "up" and "remove" not in upper case? (like "BUTTON"?)

when we use event.target.tagName, we have to put it in caps?

but why is it not the case for event.target.className?

Thank you for enlightening me.

1 Answer

Steven Parker
Steven Parker
229,744 Points
Steven Parker
Steven Parker
229,744 Points

Tag names are stored internally in upper case, so they must always be compared with all upper case to match.

But class names are stored exactly as they are used in the code, so they must be compared with the same case.