C＃RegEx匹配特定的字符串

Question

I need to match (using regex) strings that can be like this:

required: custodian_{number 1 - 9}_{fieldType either txt or ssn} optional: _{fieldLength 1-999}

So for example: custodian_1_ssn_1 is valid custodian_1_ssn_1_255 is valid

custodian or custodian_ or custodian_1 or custodian_1_ or custodian_1_ssn or custodian_1_ssn_ or custodian_1_ssn_1_ are not valid

Currently I am working with this:

(?:custodian|signer)_[1-9]?[0-9]_(?:txt|ssn)_[1-9][0-9]?(_[1-9]?[0-9]?[0-9]?)?

as my regex and my api is working to pick up: custodian_1_txt_1 custodian_1_ssn_1 custodian_1_txt_1_25 5 <---- not matching the last "5"

any thoughts?

Answer 1

You may use pattern:

^custodian(?:_[a-z0-9]+)+$

• ^ Assert position beginning of line.
• custodian Match literal substring custodian .
• (?:_[a-z0-9]+)+ Non capturing group. Multiple sequence of _ followed by alphanumerics.
• $ Assert position end of line.

You can check the correct matches here .

Obviously you can modify the pattern to add substring signer in non capturing group as:

^(?:custodian|signer)(?:_[a-z0-9]+)+$ .

Answer 2

I suggest using \\d for numbers not yours and this is my code try it:-

(?:custodian|signer)_[1-9]?[0-9]_(?:txt|ssn)_[1-9][0-9]?(_[1-9]?\d*)?

I just added a \\d value to the end of your pattern to match all end digits before another match.

Answer 3

您可以使用锚点来声明字符串的开始^和结束$ ，对于最后一部分，至少使前1-9不是可选的，否则它将匹配并在末尾加下划线：

^(?:custodian|signer)_[1-9]?[0-9]_(?:txt|ssn)_[1-9][0-9]?(_[1-9][0-9]?[0-9]?)?$

Answer 4

If you're only interested in the last digits, this super generic regex will do:

(?:.+)_(\d+)

If you do need to match the whole string, this worked:

^(?:custodian|signer)_\d+_(?:txt|ssn)(?:_\d+)?_(\d+)$