I know this regex can be simplified - .NET

Question

Here are my requirements:

• 1-80 characters
• These characters are allowed:
  • alphanumeric
  • spaces
  • _ ( ) [ ] ! # , . & * + : ' / -

The regex I have below works, but in particular I'm not sure how to reuse the character class [\w\(\)\.\-\[\]!#,&*+:'\/]

[\w\(\)\.\-\[\]!#,&*+:'\/][\w\s\(\)\.\-\[\]!#,&*+:'\/]{0,79}

Update:

Thanks for all your answers, this one did the trick

^(?!\s)[\w\s().\-!#&]{1,80}$

Answer 1

Does it really need to be 100% regex? Couldn't you just do

[\w\s\(\)\.\-\[\]!#,&*+:'\/]{1,80}

and separately verify that the first character isn't whitespace?

Answer 2

Inside a character class, only ] and \ need escapes. Even - doesn't need an escape if it's the first character of the class!

Here's the simplest regex I could reduce it to:

[- \w().[\]!#,&*+:'/]{1,80}

Answer 3

You could use a negative look ahead to check the first character is not white space. Then there is no need to reuse a character class.

(?!\s)[\w\s\(\)\.\-\[\]!#,&*+:'\/]{1,80}

Answer 4

If the first character can't be white space try this: (?!\s)[-\w\s().[\]\\!#,&*+:'/]{1,80}. You may want to "bracket" with ^ in the beginning and $ at the end ^(?!\s)[-\w\s().[\]\\!#,&*+:'/]{1,80}$, to have the regex match the whole string.