Java case insensitive regular expression

Question

I just got this:

System.out.println("КОНТАКТЫ".matches("(?i).*контакт.*"));

and it always says "false".

I tried:

System.out.println("КОНТАКТЫ".matches("(?i:.*контакт.*)"));

and:

System.out.println("КОНТАКТЫ".matches("(?i:).*контакт.*"));

and:

System.out.println("КОНТАКТЫ".matches("(?i)^.*контакт.*$"));

and many others variations but I always have "false".

How to perform case insensitive search in java correctly so I have "true" in this regexp search?

What do I do wrong?

Answer 1

What you need is to turn unicode case flag on:

System.out.println("КОНТАКТЫ".matches("(?iu).*контакт.*"));

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