Regular Expressions 101

Group 1(\G(?!^)[^\W_]*|\b(?<!\.)(?![A-Z_]+\b)[^\W_]+)

1st Alternative\G(?!^)[^\W_]*

\Gstart of current search

Negative Lookahead(?!^)

^start of line

Negated Character Class[^\W_]*

*matches any number of characters outside the set below:

\Wany non-word character

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

2nd Alternative\b(?<!\.)(?![A-Z_]+\b)[^\W_]+

\ban ASCII word boundary

Negative Lookbehind(?<!\.)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negative Lookahead(?![A-Z_]+\b)

Character Class[A-Z_]+

+matches at least one character from the set below:

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

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

\ban ASCII word boundary

Negated Character Class[^\W_]+

+matches at least one character outside the set below:

\Wany non-word character

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 2([^\W_])

Negated Character Class[^\W_]

\Wany non-word character

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

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.

25 tokens

Regular Expression

(\G(?!^)[^\W_]*|\b(?<!\.)(?![A-Z_]+\b)[^\W_]+)_([^\W_])

New

input_layout_phone_number
R.string.abc_def
KEY_ABC

$1\U$2

input_layout_phone_number
R.string.abc_def
KEY_ABC