Regular Expressions 101

Pro

Group 1(\${1,2})

\${1,2}the literal $ (36₁₀ / 44₈ / 24₁₆) , repeated between 1 and 2 times

Non-Capturing Group(?:(?!\1)[\s\S])*

*repeats the group contents below any number of times:

Negative Lookahead(?!\1)

\1the text saved by group 1

Character Class[\s\S]

\sa Unicode whitespace character

\Sany character that is not Unicode whitespace

\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.

25 tokens

(\${1,2})(?:(?!\1)[\s\S])*\1

New

This is an example $$a \text{$a$}$$. How to remove it? Another random math expression $\mathbb{R}$...

This is an example $$a \text{$a$}$$. How to remove it? Another random math expression $\mathbb{R}$...