Regular Expressions 101

Explanation

Pro

^start of line

Non-Capturing Group(?:[A-Z0-9]|[0-9][a-z])+

+repeats the group contents below at least once:

1st Alternative[A-Z0-9]

Character Class[A-Z0-9]

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

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

2nd Alternative[0-9][a-z]

Character Class[0-9]

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

Character Class[a-z]

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

$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

^(?:[A-Z0-9]|[0-9][a-z])+$

New

AA
AB
1a
1b
1A
1B
A1A
A1a
AB1
AB2
AB1a
AB2b

Aa
Ab
a1
b1
Ab1
a1a

AA
AB
1a
1b
1A
1B
A1A
A1a
AB1
AB2
AB1a
AB2b

Aa
Ab
a1
b1
Ab1
a1a