Regular Expressions 101

Pro

<athe literal text <a (case sensitive)

\ban ASCII word boundary

Positive Lookahead(?=[^>]* class="[^"]*(?<=[" ])active[" ])

Negated Character Class[^>]*

*matches any number of characters outside the set below:

>the literal > (62₁₀ / 76₈ / 3E₁₆)

class="the literal text class=" (case sensitive)

Negated Character Class[^"]*

*matches any number of characters outside the set below:

"the literal " (34₁₀ / 42₈ / 22₁₆)

Positive Lookbehind(?<=[" ])

Character Class[" ]

"the literal " (34₁₀ / 42₈ / 22₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

activethe literal text active (case sensitive)

Character Class[" ]

"the literal " (34₁₀ / 42₈ / 22₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

Positive Lookahead(?=[^>]* href="([^"]*))

Negated Character Class[^>]*

*matches any number of characters outside the set below:

>the literal > (62₁₀ / 76₈ / 3E₁₆)

href="the literal text href=" (case sensitive)

Group 1([^"]*)

Negated Character Class[^"]*

*matches any number of characters outside the set below:

"the literal " (34₁₀ / 42₈ / 22₁₆)

Global pattern flags

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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

<a\b(?=[^>]* class="[^"]*(?<=[" ])active[" ])(?=[^>]* href="([^"]*))

New

<a class="active" href="something">
<a href="something" class="active">
<a href="something" class="another-class active some-other-class">

<a class="inactive" href="something">
<a not-class="active" href="something">
<a class="active" not-href="something">