Regular Expressions 101

^start of line

Negative Lookahead(?!.*?([A-HJ-NPRT-W]).*\1)

.*?any character (except for line terminators), repeated any number of times

Group 1([A-HJ-NPRT-W])

Character Class[A-HJ-NPRT-W]

A-Hone character from A (65₁₀) to H (72₁₀) (case sensitive)

J-None character from J (74₁₀) to N (78₁₀) (case sensitive)

Pthe literal P (80₁₀ / 120₈ / 50₁₆) (case sensitive)

Rthe literal R (82₁₀ / 122₈ / 52₁₆) (case sensitive)

T-Wone character from T (84₁₀) to W (87₁₀) (case sensitive)

.*any character (except for line terminators), repeated any number of times

\1the text saved by group 1

Character Class[A-Z]+

+matches at least one character from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

$end of line

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

No unit tests · Add a test to get started

25 tokens

Regular Expression

^(?!.*?([A-HJ-NPRT-W]).*\1)[A-Z]+$

There are no unit tests, click to add some.