Regular Expressions 101

^start of line

Character Class[+]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

\d+a digit, repeated at least once

$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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^[+]?\d+$