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

PHP PHP Basics Unit Converter Number Variables

Kat Cuccia
Kat Cuccia
786 Points
Posted by Kat Cuccia
Kat Cuccia
786 Points

Why is this an invalid variable name?

One of the quiz questions in the PHP Variables section asked, "Which of the following is NOT a valid variable name?" and gave me the options of "$first_student"; "$student_"; "$1stStudent"; and "$_student." I guessed $1stStudent correctly based on it being the only option that contained something none of the others did, but I don't know if it's invalid because it contains a numeral or because it contains a capital (could be both??). Can anyone clarify please?

1 Answer