正则表达式检查 3 个大写字母、3 个数字、3 个特殊字符

Question

我想编写一个正则表达式来检查字符串是否在任何地方都有 3 个大写字母、3 个数字和 3 个特殊字符（&%#@!$）。这些字母不必一个接一个。字符串的长度也应该至少为 10。也不应该有任何空格。

所以那个字符串

aF2$Rec45yT&! - will match
aF2$Re c45yT&! - will not match
F2$R45T&!      - will not match

Answer 1

此正则表达式符合要求：

^(?=(.*?[A-Z]){3})(?=(.*?[0-9]){3})(?=(.*?[&%#@!$]){3})\S{10,}$ 

组件是：

(?=(.*?[A-Z]){3})    - lookahead to make sure there are at least 3 upper case letters
(?=(.*?[0-9]){3})    - lookahead to make sure there are at least 3 digits
(?=(.*?[&%#@!$]){3}) - lookahead to make sure there are at least 3 of the listed special characters
\S{10,}              - to make sure there is no space in input and it is at least 10 in lenght