Regular Expressions 101

Pro

^start of line

Positive Lookahead(?=(?:.*(?<one>foo))?)

Non-Capturing Group(?:.*(?<one>foo))?

?repeats the group contents below at most once:

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

Group one(?<one>foo)

foothe literal text foo (case sensitive)

Positive Lookahead(?=(?:.*(?<two>bar))?)

Non-Capturing Group(?:.*(?<two>bar))?

?repeats the group contents below at most once:

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

Group two(?<two>bar)

barthe literal text bar (case sensitive)

Positive Lookahead(?=(?:.*(?<three>baz))?)

Non-Capturing Group(?:.*(?<three>baz))?

?repeats the group contents below at most once:

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

Group three(?<three>baz)

bazthe literal text baz (case sensitive)

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.

26 tokens

^(?=(?:.*(?<one>foo))?)(?=(?:.*(?<two>bar))?)(?=(?:.*(?<three>baz))?)

foo bar baz
foo baz bar
baz bar foo
foo bar
foo baz
bar baz
foo
bar
baz

foo bar baz
foo baz bar
baz bar foo
foo bar
foo baz
bar baz
foo
bar
baz