php - RegEx to check 3 or more consecutive occurrences of a character -

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i want check input string validate proper text.

a. want users allow writer alphanumeric characters including period, comma, hyphen , round bracket ()

b. however, dont want users enter number 3 or more digits together. eg: 12 allowed while 185 not.

c. dont want users enter strings "............." or "----------" or "aaaaaaaaaaaaaa" or "bbbbbbbb" etc.

please suggest regular expression same.

you can use regex:

(?!.*(.)\1{2})^[a-za-z0-9.,()-]*$

it uses negative lookahead (?!.*(.)\1{2}) ensure there no group of 3 repetitions of of characters.

then uses regex ^[a-za-z0-9.,()-]*$ ensure string made of alphabets, numbers, period, comma, parenthesis , hyphen.

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