Regular Expressions 101

Explanation

Pro

1st Alternative(?<!^|[A-Z\p{P}])[A-Z]

Negative Lookbehind(?<!^|[A-Z\p{P}])

1st Alternative^

^start of line

2nd Alternative[A-Z\p{P}]

Character Class[A-Z\p{P}]

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

\p{P}a punctuation character

Character Class[A-Z]

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

2nd Alternative(?<=\p{P})\p{P}

Positive Lookbehind(?<=\p{P})

\p{P}a punctuation character

3rd Alternative(?<=[a-z])(?=\d)

Positive Lookbehind(?<=[a-z])

Character Class[a-z]

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

Positive Lookahead(?=\d)

\da digit

4th Alternative(?<=\d)(?=[a-z])

Positive Lookbehind(?<=\d)

\da digit

Positive Lookahead(?=[a-z])

Character Class[a-z]

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

5th Alternative(?<=[A-Z])(?=\d)

Positive Lookbehind(?<=[A-Z])

Character Class[A-Z]

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

Positive Lookahead(?=\d)

\da digit

6th Alternative(?<=\d)(?=[A-Z])

Positive Lookbehind(?<=\d)

\da digit

Positive Lookahead(?=[A-Z])

Character Class[A-Z]

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

7th Alternative(((?<!^)(?<!['([{])[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))

Group 1(((?<!^)(?<!['([{])[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))

8th Alternative(?<!^)(?=[[({&])

9th Alternative(?<=[)\]}!&}])

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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

(?<!^|[A-Z\p{P}])[A-Z]|(?<=\p{P})\p{P}|(?<=[a-z])(?=\d)|(?<=\d)(?=[a-z])|(?<=[A-Z])(?=\d)|(?<=\d)(?=[A-Z])|(((?<!^)(?<!['([{])[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))|(?<!^)(?=[[({&])|(?<=[)\]}!&}])

New

ANewTestTitleThat'sATestHELLOworldHELLOWorldHELLO-WORLDTest123Hello&WorldTest!T.E.S.T(Test)T-E-S-T[Test]T_E_S_T{Test}'Test'