perl regex 查找任何 5 的倍数 [英] perl regex to find any number that is a multiple of 5

问题描述

Perl 正则表达式查找任何 5 的倍数.

Perl regex to find any numbers that is multiple of 5.

我尝试使用 =~/[5]+/ 但它只找到包含 5 的数字，而不是 5 的倍数.

I tried using =~ /[5]+/ but it is finding only numbers which contains 5, but not multiple of 5.

还要找出长度为 5 的倍数的字符串.

And also to find string whose length is multiple of 5.

推荐答案

我会回答你的第二个问题:还要找出长度是 5 的倍数的字符串.

I will answer your second question: And also to find string whose length is multiple of 5.

这比数字部分更适合正则表达式(已回答)，只需将 5 个字符分组并匹配它们的倍数

That is more suitable for regex than the number part (that has been answered), just group 5 characters and match multiples of them

^(?:.{5})*$

在 Regexr 上查看 此处

See it here on Regexr

^ 和 $ 匹配字符串的开头和结尾.

^ and $ matches the start and the end of the string.

.{5} 匹配 5 个字符(不使用 s 修饰符时的换行符除外)

.{5} matches 5 characters (except newlines when you don't use the s modifier)

(?:.{5})* 重复组的内部 0 次或更多次 ==> 这也将匹配空字符串！如果您不想要这个并且仅从至少 5 的字符串长度开始，请使用 + 量词表示 1 或更多:^(?:.{5})+$

(?:.{5})* repeats the inner part of the group 0 or more times ==> this will also match on the empty string! If you don't want this and start only from a string length of at least 5 use the + quantifier means 1 or more: ^(?:.{5})+$

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