php split string by capital letter but ignore TLA. Also with TLA at the end of the word

Question

The solution can apparently be this:

$string = 'TodayILiveInTheUSAWithSimon';
$regex = '/(?<!^)((?<![[:upper:]])[[:upper:]]|[[:upper:]](?![[:upper:]]))/';
$string = preg_replace( $regex, ' $1', $string );

But this case "TodayILiveInTheUSAWithSimonUSA" does not work well because it returns "Today I Live In The USA With Simon US A" the last letter appears separated. Do you know a complete solution?

Possible duplicate of [RegEx to split camelCase or TitleCase (advanced)](https://stackoverflow.com/questions/7593969/regex-to-split-camelcase-or-titlecase-advanced) — Sebastian Proske, Feb 01 '18 at 15:16
You may use: [`(?<=[A-Z])[A-Z]{2}(*SKIP)(*F)|(?<=[A-Za-z])(?=[A-Z])`](https://regex101.com/r/X3gIix/1/) — anubhava, Feb 01 '18 at 15:32

KyleFairns · Answer 1 · 2018-02-01T15:58:02.480

1

(?<!^)(?![[:upper:]]$)((?<![[:upper:]])[[:upper:]]|[[:upper:]](?![[:upper:]]))

Added in a negative lookahead to make sure it isn't matching the capital at the end of the string too.

The only times you'll want to separate this is if you're ending on a one letter word anyway, which is unlikely, so shouldn't have too much backlash

edited Feb 01 '18 at 15:58

answered Feb 01 '18 at 15:46

KyleFairns

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score 0 · Answer 2 · answered Feb 01 '18 at 15:39

If you just want to skip all 3 uppercase letters then using PHP (PCRE) you may be able to use this regex:

(?<=[A-Z])[A-Z]{2}(*SKIP)(*F)|(?<=[A-Za-z])(?=[A-Z])

Code:

$re = '/(?<=[A-Z])[A-Z]{2}(*SKIP)(*F)|(?<=[A-Za-z])(?=[A-Z])/';

$result = preg_replace($re, ' ', $str);

Explanation:

(?<=[A-Z])[A-Z]{2}(*SKIP)(*F): If we match 2 uppercase letters and have a uppercase letter at previous position then skip (fail) that pattern
|: OR
(?<=[A-Za-z])(?=[A-Z]): If have any letter at previous position and have a uppercase letter at next position

score 0 · Answer 3 · answered Feb 01 '18 at 16:19

Regex: (?:[A-Z]+|[A-Z][a-z]+)\K(?=[A-Z]) Substitution: " " (space)

Details:

(?:) Non capturing group
[] Match a single character present in the list
+ Matches between one and unlimited times
| Or
\K Resets the starting point of the reported match.
(?=) Positive Lookahead

Regex demo

Code:

$text = 'TodayILiveInTheUSAWithSimon';
$text = preg_replace("/(?:[A-Z]+|[A-Z][a-z]+)\K(?=[A-Z])/", " ", $text);
print_r($text);

Output: Today I Live In The USA With Simon

php split string by capital letter but ignore TLA. Also with TLA at the end of the word

3 Answers3