Regex in PHP to find last upcase char from the Camel Case

Question

I want to match in PHP the last capitalize (http://php.net/manual/en/function.ucfirst.php) character in the string.

To add to the complication I want to ignore everything after a different string, e.g. a sequence of uppercases that not capitalized or in camel case style.

Here follow some examples of what should and shouldnt match

Matches:

Foobar => Expected char: F
fooBar  => Expected char: B
A_fooBar  => Expected char: B
fooBAR => Expected char: B (Most complicated situation)

No matches:

foo A_bar
foobar
foo bar foo bar
foobar /* Comment */

So far I've tried the following regex:

(?!A_)[A-Z](?!((?!/\*).)*\*/)

but with no luck. From Question: the Regexp match any uppercase characters except a particular string (Very similar situation)

@edit

And another regex

/([A-Z])[^A-Z\W]*$/

http://phpfiddle.org/main/code/dyq-3h7

Answer 1

I believe this matches where appropriate, and will ignore your other examples as well.

^\w*?(?<![A-Z_])([A-Z])(?!_)

See this fiddle

Answer 2

If I understand you right, you basically want the last uppercase letter that is not preceded by another uppercase letter. In that case, try this:

/.*(?<![A-Z])([A-Z])/

Then just get the first subpattern.

Answer 3

try this

/([A-Z])([A-Za-z]|[^_\*\/])*$/

this works with every of your examples:

http://phpfiddle.org/main/code/sgb-7m