Regular Expressions 101

Explanation

Pro

\Bnot a Unicode word boundary

Negative Lookbehind(?<!@)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Group 1(\w{1,31})

\w{1,31}a Unicode word character, repeated between 1 and 31 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

\B(?<!@)@(\w{1,31})

New

@romeo went to @juliet and said hi, I'm @romeo

<a href="/u/\1">\g<0></a>

@romeo went to @juliet and said hi, I'm @romeo