Regular Expressions 101

Pro

athe literal a (97₁₀ / 141₈ / 61₁₆) (case sensitive)

Negative Lookbehind(?<!\bca(?=t\b))

\ban ASCII word boundary

cathe literal text ca (case sensitive)

Positive Lookahead(?=t\b)

tthe literal t (116₁₀ / 164₈ / 74₁₆) (case sensitive)

\ban ASCII word boundary

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

a(?<!\bca(?=t\b))

New

I am a cat in a hat in a car" except where it appears in the word "cat":