Regular Expressions 101

1st Alternative([A-Z]+)\d+-\1\d+

Group 1([A-Z]+)

Character Class[A-Z]+

+matches at least one character from the set below:

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

\d+a digit, repeated at least once

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\1the text saved by group 1

\d+a digit, repeated at least once

2nd Alternative(?!.*-)^.*$

Negative Lookahead(?!.*-)

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

^start of line

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

$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

([A-Z]+)\d+-\1\d+|(?!.*-)^.*$

New

E1-E9
E1-E1
E1-E99
A1-A999
AB5-AB77
A1-B9
E1-EE9
E1 1EE
E1
AB9 4CD