CODEWITHSUNDEEP
c#regex
mikeysee
mikeysee

Reputation: 1763

Why does this Regular Expression not return the correct match?

I am trying to return part of a string, I want to return everything before the fist slash:

EC22941C/02/ORI

Should give me: EC22941C

I have used http://www.regexr.com/ to build up my expression:

(EC.+?)\/.+

When tested against my text:

EC22941C/02/ORI

It correctly tells me that the first group is

EC22941C

When I put it into C#:

 public static string GetInstructionRef(string supplierReferenceId)
    {
        // The instruciton ref is the bit before the slash            
        var match = Regex.Match(supplierReferenceId, @"(EC.+?)\/.+");

        if (match == null || match.Groups.Count == 0)
            return "";

        // Return the first group which is the instruction ref
        return match.Groups[0].Value;
    }

The result I get back is:

EC22941C/02/ORI

I have tried a number of different patterns and they all seem to do the same thing.

Does anyone have any idea what im doing wrong?

Upvotes: 0

Views: 61

Answers (3)

hwnd
hwnd

Reputation: 70722

The issue is that you're returning the wrong group index, 0 will return the entire match while 1 returns the matched context of the capturing parentheses — numbered from left to right.

return match.Groups[1].Value;

Upvotes: 1

vks
vks

Reputation: 67968

^EC[^\/]+

You can simply use this and avoid using groups.See demo.

https://regex101.com/r/bW3aR1/6

string strRegex = @"^EC[^\/]+";
Regex myRegex = new Regex(strRegex, RegexOptions.Multiline);
string strTargetString = @"EC22941C/02/ORI";

foreach (Match myMatch in myRegex.Matches(strTargetString))
{
  if (myMatch.Success)
  {
    // Add your code here
  }
}

Upvotes: 1

wings
wings

Reputation: 801

you should use match.Groups[1].Value.

match.Groups[0].Value returns the whole string (if it matches the pattern).

Also, you'd want to change your if condition as well. :)

Upvotes: 0

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