Regular Expressions 101

Group 1({{(?:[1-9]|[1-9]\d)}})

{{the literal text {{

Non-Capturing Group(?:[1-9]|[1-9]\d)

1st Alternative[1-9]

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

2nd Alternative[1-9]\d

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\da digit

}}the literal text }}

Negative Lookbehind(?<!^(?:[^]*\1){2})

^start of line

Non-Capturing Group(?:[^]*\1){2}

{2}repeats the group contents below exactly 2 times:

[^]*any character, including newline, repeated any number of times

\1the text saved by group 1

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.

26 tokens

Regular Expression

({{(?:[1-9]|[1-9]\d)}})(?<!^(?:[^]*\1){2})

New

{{1}}{{2}}{{3}}{{4}}{{5}}{{1}}
{{11}}{{12}}{{13}}{{14}}{{12}}{{11}}
{{21}}{{22}}{{22}}{{24}}{{21}}{{21}}