Java difficult regular expression, how to mathc groups (tripples)?

Question

How can I check in regex that 3 of the same digits must appear next to each other and that 1x or more times?

Answer 1

you can use below regular expression:

(\d)\1\1

Answer 2

test.matches("((a)\\1*){3}")

Answer 3

此正则表达式应该以您预期的方式工作：

\d{3}