It's common to see a developer use a StringBuilder or basic string concatenation to concatenate strings in .NET code.

You'll usually see something like this:

string comma = ",";
StringBuilder sb = new StringBuilder();
sb.Append("Donn");
sb.Append(comma);
sb.Append("Felker");
sb.Append(comma);
sb.Append("Jiu-Jitsu");
sb.ToString(); 

And this will return "Donn,Felker,Jiu-Jitsu"

But the .NET framework has something built in just for doing this type of operation.

Its called the CommaDelimitedStringCollection and it's located in System.Configuration namespace. What it allows you to do is to add items to a collection and then just access the "ToString" method of the class to return the value of the collection, delimited by comma's.

Here it is, in action:

CommaDelimitedStringCollection coll = new CommaDelimitedStringCollection();
coll.Add("Donn");
coll.Add("Felker");
coll.Add("Jiu-Jitsu");
coll.ToString();

This will return "Donn,Felker,Jiu-Jitsu".

Much easier, much nicer.

Enjoy.