Regular Expressions 101

\{the literal { (123₁₀ / 173₈ / 7B₁₆)

Group 1([\s\S]*)

Character Class[\s\S]*

*matches any number of characters from the set below:

\sany whitespace character

\Sany non-whitespace character

\}the literal } (125₁₀ / 175₈ / 7D₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

\{([\s\S]*)\}

New

$str='\add[sometext]{\begin{equation}\label{eqn:3}
f_{1} =
\begin{cases}}
\beta_{1} + \beta_{2}f_{2} & f_{2}\leq \gamma\\
\beta_{1} + \beta_{2}\gamma + \beta_{4}(f_{2}-\gamma) & f_{2} >\gamma
\end{cases}sdsdssd,
\end{equation}}'