Regular Expressions 101

Pro

^start of line

Positive Lookahead(?=(?:[0-9]*[a-zA-Z]){3})

Non-Capturing Group(?:[0-9]*[a-zA-Z]){3}

{3}repeats the group contents below exactly 3 times:

Character Class[0-9]*

*matches any number of characters from the set below:

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

Character Class[a-zA-Z]

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

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

Character Class[a-zA-Z0-9]{14}

{14}matches exactly 14 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)

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.

27 tokens

^(?=(?:[0-9]*[a-zA-Z]){3})[a-zA-Z0-9]{14}$

New

abcdefghijklmn
1bcde2ghi3klmn
1a34b678C01234

12345678901234
a2345678901234
a234567890123b