Prevent consecutive meaningless characters from occurring in JS or PHP

Question

Users often send many meaningless characters such as "Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh"

Is there any way to prohibit it? Either js or php is fine.

Thanks

Answer 1

Regular judgment

var re = /(.){3,}/u;  // 匹配同一个字符4次以上
re.test(str); // true = 同一字符4次或以上

preg_match('/(.){3,}/u', $str); // 1 = 同一个字4次或以上

Send a JS test picture:

Note:

The
1. u

   modifier after the regular is used to support Unicode wide characters

2. {3,} means matching 3 times or more. Since the previous (.) has already been matched once, the entire limited number is 1 greater than this number. In addition, this number can be changed according to your own needs.