Regular Expressions 101

_{3}the literal _ (95₁₀ / 137₈ / 5F₁₆) , repeated exactly 3 times

Positive Lookahead(?=.*[a-zA-Z_])

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

Character Class[a-zA-Z_]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 1(.*[a-zA-Z_])

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

Character Class[a-zA-Z_]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

_{3}the literal _ (95₁₀ / 137₈ / 5F₁₆) , repeated exactly 3 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

_{3}(?=.*[a-zA-Z_])(.*[a-zA-Z_])_{3}

New

___string_string___ 
___test___
__something__
___sda1231___
______

___string_string___ 
___test___
__something__
___sda1231___
______