Regular Expressions 101

Pro

1st Alternative(?<=\bfoo\b.*)\d*\.?\d+

Positive Lookbehind(?<=\bfoo\b.*)

\ban ASCII word boundary

foothe literal text foo (case sensitive)

\ban ASCII word boundary

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

\d*a digit, repeated any number of times

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

2nd Alternative\d*\.?\d+(?=.*?\bfoo\b)

\d*a digit, repeated any number of times

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Positive Lookahead(?=.*?\bfoo\b)

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

\ban ASCII word boundary

foothe literal text foo (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.

26 tokens

(?<=\bfoo\b.*)\d*\.?\d+|\d*\.?\d+(?=.*?\bfoo\b)

2-4 foo
foo 4-6
bar 8
should match

2, 4
4, 6

2-4 foo
foo 4-6
bar 8
should match

2, 4
4, 6