Regular Expressions 101

^start of line

Group 1(\S+)

\S+any non-whitespace character, repeated at least once

\s+any whitespace character, repeated at least once

Negative Lookahead(?!\1)

\1the text saved by group 1

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

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

Regular Expression

^(\S+)\s+(?!\1).*

New

43,186 43,186
296,531 296,531
108086 108086
abcdef abcdef
Capture This
497,802 497,802
200,062 300,062
Not Same
202232 252232
4,324,452 4,324,452