Free Regex Basics Flashcards

Regular expressions are twenty symbols that turn text problems into one-liners — and they show up in every language, editor, and interview. These cards drill the core tokens until they read like words.

Study these 10 starter cards

QUESTION

Tap the card to reveal the answer

QWhat does . match in a regex?

AAny single character (except newline by default)

QWhat does \d match?

AA digit 0–9

QWhat does + mean after a token?

AOne or more of it

QWhat does * mean after a token?

AZero or more of it

QWhat does ^ and $ anchor?

AStart and end of the string (or line)

QWhat does [abc] match?

AOne character: a, b, or c

QWhat does \w match?

AA word character: letter, digit, or underscore

QWhat does ? mean after a token?

AZero or one — makes it optional (also makes quantifiers lazy: +?)

QWhat do parentheses ( ) do?

AGroup tokens and capture the matched text

QWhat does a|b mean?

AMatch a OR b

Turn these into lasting memory

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How to study regex basics with flashcards

One fact per card. For every token, recall a concrete match example ("\d+ matches 42") — regex is learned in examples, not definitions.
Rate honestly. After each card, choose Again, Hard, Good, or Easy — the spaced repetition algorithm uses your answer to decide when the card returns, right before you'd forget it.
A few minutes daily beats marathons. Ten new cards a day is roughly 3,650 a year, retained. Deep dives: Flashcards for programmers · Interleaving: mix topics, learn more · How to make flashcards that actually work.

Free Regex Basics Flashcards

Study these 10 starter cards

Turn these into lasting memory

How to study regex basics with flashcards

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