Regular Expressions 101

Pro

1st Alternative^(123-(?:(?![aA][a-zA-Z]*).*)-456)

^start of line

Group 1(123-(?:(?![aA][a-zA-Z]*).*)-456)

123-the literal text 123-

Non-Capturing Group(?:(?![aA][a-zA-Z]*).*)

Negative Lookahead(?![aA][a-zA-Z]*)

Character Class[aA]

athe literal a (97₁₀ / 141₈ / 61₁₆) (case sensitive)

Athe literal A (65₁₀ / 101₈ / 41₁₆) (case sensitive)

Character Class[a-zA-Z]*

*matches any number of characters from the set below:

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

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

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

-456the literal text -456

2nd Alternative(123-456)$

Group 2(123-456)

123-456the literal text 123-456

$end of line

Global pattern flags

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

^(123-(?:(?![aA][a-zA-Z]*).*)-456)|(123-456)$

New

123-456
123-7-456
123-Apple-456
123-0-456
123-Alphabet-456
123- -456
123--456
123-b-456
123-bbbbb-456
123-Hello-456

123-456
123-7-456
123-Apple-456
123-0-456
123-Alphabet-456
123- -456
123--456
123-b-456
123-bbbbb-456
123-Hello-456