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

CSS CSS Selectors Going Further with Attribute Selectors and Pseudo-Classes Substring Matching Attribute Selectors - "Begins With" and "Ends With"

Nicholas Wallen
Nicholas Wallen
12,278 Points
Posted by Nicholas Wallen
Nicholas Wallen
12,278 Points

Dumb Question: Why does he repeat the background size value twice?

background-size: 18px 18px;

So I put 18px only once, and got the same result. How come Guil put it twice?

2 Answers

Steven Parker
Steven Parker
231,236 Points
Steven Parker
Steven Parker
231,236 Points

The first value is width, the second one is height.

If you specify only the width, the height is set to "auto". So if the image being displayed is square, there would be no visible difference between one value and two identical values.

Peter Huang
Peter Huang
5,427 Points
Peter Huang
Peter Huang
5,427 Points

questions and answers are great. I was wondering the same thing but thank god for this answer