Regular Expressions 101

Explanation

Pro

^start of line

Character Class[a-fA-F0-9]{2}

{2}matches exactly 2 characters from the set below:

a-fone character from a (97₁₀) to f (102₁₀) (case sensitive)

A-Fone character from A (65₁₀) to F (70₁₀) (case sensitive)

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

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Character Class[a-fA-F0-9]{2}

{2}matches exactly 2 characters from the set below:

a-fone character from a (97₁₀) to f (102₁₀) (case sensitive)

A-Fone character from A (65₁₀) to F (70₁₀) (case sensitive)

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

$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-fA-F0-9]{2}:[a-fA-F0-9]{2}$

New

02:222222
fail
00:20
expected output: pass
00:202
expected ouput: fail
00:2z
expected output: fail
000:2
expected ouput: fail

02:222222
fail
00:20
expected output: pass
00:202
expected ouput: fail
00:2z
expected output: fail
000:2
expected ouput: fail