Regular Expressions 101

Group 1((<)(\/|)(?!a|h1)([a-zA-Z0-9]+))

Group 2(<)

<the literal < (60₁₀ / 74₈ / 3C₁₆)

Group 3(\/|)

1st Alternative\/

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

2nd Alternative — matches an empty string

Negative Lookahead(?!a|h1)

1st Alternativea

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

2nd Alternativeh1

h1the literal text h1 (case sensitive)

Group 4([a-zA-Z0-9]+)

Character Class[a-zA-Z0-9]+

+matches at least one character 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)

Global pattern flags

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

((<)(\/|)(?!a|h1)([a-zA-Z0-9]+))

New

<!-- Comments Testing -->
<div id="page"><div id="header"><h1><a href="#">Burger Pointer</a></h1><ul class="left"><li><a href="#">Menu</a></li><li><a href="#">Location</a></li><li><a href="#">About Us</a></li><li><a href="#">BP Gear</a></li></ul></div></div>

Substitution

\n\1