regex

[Frank]

Hi,
I'm beginning to understand regex (regular expressions), but I think there's
a better way to do the next thing. I use 2 steps, is it possible to do it in
1 step?

<img somestuff src="found.gif" otherstuff>

Is it possible to get the index and length of 'found.gif' in 1 regex match?

Thanks in advance
Frank

 

[AlexS]

Frank,
yes.

See Captures and Groups collections in Match. Both Capture and Group objects
have Index and Length properties.

HTH
Alex

 

[Frank]

Thanks Alex,
but I was rather hoping for an example.
Frank

 

[AlexS]

Frank,

here is sample code

Regex r = new Regex(@"<img.+src=(+.+).+");

string str = "<img somestuff src=\"found.gif\" otherstuff>";

Match m = r.Match(str);

if (m.Success) {

foreach (Group g in m.Groups) {

Console.WriteLine("Group: {0}, starts {1}, length {2}",

g.Value, g.Index, g.Length);

}

}

This produces output:

Group: <img somestuff src="found.gif" otherstuff>, starts 0, length 43
Group: found.gif, starts 21, length 9

You can produce same with Captures



Alex

 

[AlexS]

Noticed that some backslahes were eaten by paste. Check that reg.exp is
Regex(@"\<img.+src\=\x22(\w+\.\w+)\x22.+");

Alex

 

[Jeff Johnson [MVP: VB]]

here is sample code

Hopefully Frank can convert your C# to VB without much trouble....

 

[Frank]

thanks Alex, now I understand what is meant by groups
Frank