Using backreference wit php preg_match_all

Question

I'am quite new in regex and php but I'm facing an issue I can't handle alone.

I've prepared this regex to find patterns starting with upper-case letter. It could sounds something like :

• capture any pattern that

• starts with one or more Upper-case letter

• then one or more any letter or character in the list

• then a space, or punctuation mark

• and I use a backreference to set I want those pattern up to 3 times :

   ([A-ZÁÀÂÄÉÈÊËÍÌÎÏÓÒÔÖÚÙÛÜ]{1,}[a-zàáâãäåçèéêëìíîïðòóôõöùúûüýÿ;:«0-9]{1,}[\\s-….?,;]\\1{1,3}) 

According to https://regex101.com/r/pB3nY7/2 it works as a javascript regex but not as a php regex.

I've rade the other posts and make sure :

• I use single quotes instead of double quotes

• and I "protected" the \\ in my php script :

   '#([A-ZÁÀÂÄÉÈÊËÍÌÎÏÓÒÔÖÚÙÛÜ]{1,}[a-zàáâãäåçèéêëìíîïðòóôõöùúûüýÿ;:«0-9]{1,}[\\\\s-….?,;]\\\\1{1,3})#' 

But it still can't match any pattern starting with a Upper-case letter.

Thank you in advance for all advice you may provide,

Regards,

Charles

Answer 1

我已经在此网站http://www.phpliveregex.com/上对其进行了测试：

(^[A-ZÁÀÂÄÉÈÊËÍÌÎÏÓÒÔÖÚÙÛÜ]{1,}[a-zàáâãäåçèéêëìíîïðòóôõöùúûüýÿ;:«0-9]{1,}[\s-….?,;]{1,1}){1,3}

Answer 2

To be more generalist, you could use unicode properties:

^(\p[Lu}+[\p{Ll};:«0-9]+[\s\p{P}]){1,3}

Where \\p[Lu} stands for an uppercase letter, \\p{Ll} a lowercase letter and \\p{P} a punctuation.

preg_match('/^(\p[Lu}+[\p{Ll};:«0-9]+[\s\p{P}]){1,3}/', $string, $match);