Regular Expressions 101

Explanation

Pro

^start of line

Group pattern1(?P<pattern1>(?P<pattern2>^[0-9]+$)|.*)

1st Alternative(?P<pattern2>^[0-9]+$)

Group pattern2(?P<pattern2>^[0-9]+$)

^start of line

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

$end of line

2nd Alternative.*

.*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.

25 tokens

^(?P<pattern1>(?P<pattern2>^[0-9]+$)|.*)$

New

12345678
123ert
1244
erty

12345678
123ert
1244
erty