Regular Expressions 101

^start of line

Non-Capturing Group(?:BE)?

?repeats the group contents below at most once:

BEthe literal text BE (case sensitive)

\s*?any whitespace character, repeated any number of times

Character Class[0-1]?

?matches at most one character from the set below:

0-1one character from 0 (48₁₀) to 1 (49₁₀)

Group 1((\d[. ]*){9})

Group 2(\d[. ]*){9}

{9}repeats the group contents below exactly 9 times:

\da digit

Character Class[. ]*

*matches any number of characters from the set below:

.the literal . (46₁₀ / 56₈ / 2E₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

$end of line

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.

Search reference

Regular Expression

^(?:BE)?\s*?[0-1]?((\d[. ]*){9})$

Test String
New

BE  0123.321.123
BE0123.321.123
BE0123 321 123
1123.321.123
123.321.123
123321123
BE1233221221
BE123322122
BE 0123.....  321  122
BE 01 23 32 11 23
aae233432233 23343

Regular Expression

Test StringNew

Test String
New