Regular Expressions 101

Group 1(\d+)

\d+a Unicode decimal digit, repeated at least once

Non-Capturing Group(?:\s*x\s*(\d+))?

?repeats the group contents below at most once:

\s*a Unicode whitespace character, repeated any number of times

xthe literal x (120₁₀ / 170₈ / 78₁₆) (case sensitive)

\s*a Unicode whitespace character, repeated any number of times

Group 2(\d+)

\d+a Unicode decimal digit, repeated at least once

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.

Search reference

Regular Expression

(\d+)(?:\s*x\s*(\d+))?

New

44
42 x 54
Steel