Why preg_match(“/[^(22|75)]/”, “25”) returns false?

Question

I want to test that a given string does not belong to the following group of strings: 22 75.

Could anyone please tell why PHP\'s preg_match(\"/[^(22|75)]/\

Answer 1

^ inside of [...] is a negation of a character list. (22|76)

Regex multiple character negation is a very tricky subject and can't be easily resolved.

But you could invert the return result of preg_match function ie.:

if(!preg_match('@22|76@', '25', $matches))
    doSomething();