C.W.K.
Stream
Quiz · 5 questions

🔤 Character Classes & Basics

Building blocks: literals, dots, classes, anchors, boundaries

Level 0Pattern-Curious
0 XP0/90 lessons0/15 achievements
0/100 XP to next level100 XP to go0% complete

Quiz

01Which class matches a single hex digit (case-insensitive)?
Hint
Hex needs 0-9 AND letters A-F.
02Which character does . NOT match by default?
Hint
What does the dot famously NOT match?
03What's wrong with [A-z] as a way to match any letter?
Hint
ASCII codepoint order matters.
04What's the difference between .* and [^x]* on a multi-line input?
Hint
Negated classes don't have the dot's no-newline rule.
05Which option correctly describes \b?
Hint
Zero-width — checks position, not character.
Spotted a bug or have feedback on this page?Report an Issue

Comments 0

🔔 Reply notifications (sign in)
Sign inPlease sign in to comment.

No comments yet — be the first.