用于防止字符串中出现 5 个或更多特殊字符的正则表达式模式

Question

Want a pattern in HTML input field to not accept string with 5 or more consecutive special symbol (.@#$%^&*).

"abc@@##xy" : accept
"@@##!" : reject
"abc" : accept
"abc@@##@xy" : reject
"abc@@##xy@@##" : accept
"abc@@##xy@@##@" : reject

Answer 1

You could use a negative lookahead with a . to prevent the appearance of 5 consecutive special chars in the string with

/^(?:(?![!@#$%^&*]{5,}).)*$/

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[,@#$%^&*]{5,} matches 5 or more of the characters ! , @ , # , $ , % , ^ , & , * (consecutively)

(?,[!@#$%^&*]{5,}) adds a negative lookahead to find a places in the string not followed by 5 consecutive 'special' characters

adding a . with a * quantifier matches any number of characters after such a position in the string, while the ^ and $ limit it to the beginning and end of a single line

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regex101