Regular Expressions 101

Pro

Positive Lookbehind(?<=Q)

Qthe literal Q (81₁₀ / 121₈ / 51₁₆) (case sensitive)

Non-Capturing Group(?:\d+(?![.\d])|\d+\.\d+(?![.\d]))

1st Alternative\d+(?![.\d])

\d+a digit, repeated at least once

Negative Lookahead(?![.\d])

Character Class[.\d]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

2nd Alternative\d+\.\d+(?![.\d])

\d+a digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Negative Lookahead(?![.\d])

Character Class[.\d]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

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

(?<=Q)(?:\d+(?![.\d])|\d+\.\d+(?![.\d]))

New

Q232.1232 K1232.232323
Q232 K1232.232323
Q232.1232
K1232.2323 Q232.1232
R232.1232 K1232.232323
Q232.12.32 K1232.232323
Q232. K1232.232323

Q232.1232 K1232.232323
Q232 K1232.232323
Q232.1232
K1232.2323 Q232.1232
R232.1232 K1232.232323
Q232.12.32 K1232.232323
Q232. K1232.232323