Regular Expressions 101

Pro

(?i)applies the following effective flags to the remainder of the pattern: gmi

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

\ba Unicode word boundary

Group 1([1-9][0-9]{3} ?[a-z])

Character Class[1-9]

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

Character Class[0-9]{3}

{3}matches exactly 3 characters from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

?optionally matches the literal (32₁₀ / 40₈ / 20₁₆)

Character Class[a-z]

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

Character Class[a-z]*

*matches any number of characters from the set below:

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

+the literal (32₁₀ / 40₈ / 20₁₆) , repeated at least once

Group 2([a-z])

Character Class[a-z]

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

Character Class[a-z]*

*matches any number of characters from the set below:

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

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

(?i)\b([1-9][0-9]{3} ?[a-z])[a-z]* +([a-z])[a-z]*

New

1234 Alpha Bee

\1\2

1234 Alpha Bee