Regular Expression

Question

I want regular expression that checks that the string doesnt start with an empty space.

Some what like this i want to do :

Is the below ValidationExpression right for it :

string ValidationExpression = @"/^[^ ]/";

if (!String.IsNullOrEmpty(GroupName) && !Regex.IsMatch(GroupName, ValidationExpression))
{    
}

Answer 1

Something like this, maybe :

/^[^ ]/

And, for a couple of notes about that :

• The first ^ means "string starts with"
• The [^ ] means "one character that is not a space"
• And the // are regex delimiter -- not sure if they are required in C#, though.

Answer 2

How about "^\S" This will make sure that the first character is not a whitespace character.

Answer 3

just a suggestion, you can also use

   if(GroupName.StartsWith(string.Empty)); // where GroupName == any string

Answer 4

Regex rx = new Regex(@"^\s+");

You can check with

  Match m1 = rx.Match("   ");  //m1.Success should be true
  Match m2 = rx.Match("qwerty   ");  //m2.Success should be false