Regular Expressions 101

Negative Lookbehind(?<!&#([0-46-9]\d|5[0-8]))

&#the literal text &#

Group 1([0-46-9]\d|5[0-8])

1st Alternative[0-46-9]\d

Character Class[0-46-9]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

6-9one character from 6 (54₁₀) to 9 (57₁₀)

\da digit

2nd Alternative5[0-8]

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

Character Class[0-8]

0-8one character from 0 (48₁₀) to 8 (56₁₀)

Negative Lookbehind(?<!&#\d{3})

&#the literal text &#

\d{3}a digit, repeated exactly 3 times

Negative Lookbehind(?<!&[a-z])

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]

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

Negative Lookbehind(?<!&[a-z]{2})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{2}

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

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

Negative Lookbehind(?<!&[a-z]{3})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{3}

{3}matches exactly 3 characters from the set below:

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

Negative Lookbehind(?<!&[a-z]{4})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{4}

{4}matches exactly 4 characters from the set below:

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

Negative Lookbehind(?<!&[a-z]{5})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{5}

{5}matches exactly 5 characters from the set below:

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

Negative Lookbehind(?<!&[a-z]{6})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{6}

{6}matches exactly 6 characters from the set below:

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

Negative Lookbehind(?<!&[a-z]{7})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{7}

{7}matches exactly 7 characters from the set below:

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

Negative Lookbehind(?<!&[a-z]{8})

&the literal & (38₁₀ / 46₈ / 26₁₆)

Character Class[a-z]{8}

{8}matches exactly 8 characters from the set below:

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

;the literal ; (59₁₀ / 73₈ / 3B₁₆)

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

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.

Search reference

Regular Expression

(?<!&#([0-46-9]\d|5[0-8]))(?<!&#\d{3})(?<!&[a-z])(?<!&[a-z]{2})(?<!&[a-z]{3})(?<!&[a-z]{4})(?<!&[a-z]{5})(?<!&[a-z]{6})(?<!&[a-z]{7})(?<!&[a-z]{8});\)

New

Should work
&#59;)
;)
hey;)
nbsp;)

Should NOT work
&nbsp;)
&#600;)
&#10;)

Substitution