Regular Expressions 101

Pro

^start of line

Foo:the literal text Foo: (case sensitive)

Non-Capturing Group(?: .*?2,([a-z]))?

?repeats the group contents below at most once:

the literal (32₁₀ / 40₈ / 20₁₆)

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

2,the literal text 2,

Group 1([a-z])

Character Class[a-z]

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

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

$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.

25 tokens

Regular Expression

^Foo:(?: .*?2,([a-z]))?.*$

New

Foo: 2,b,1,a,3,c
" -> match, $1 = "b"
Foo: 1,a,2,b,3,c
" -> match, $1 = "b"
Foo: 1,a,3,c,2,b
" -> match, $1 = "b"
Foo: 2,b
"         -> match, $1 = "b"
Foo: 1,a,3,c
"     -> match, $1 = ""
Fuu: 1,a,2,b,3,c
" -> no match.