Manipulate string problem

Question

If I have a string variable with value as follows :-

string mystring = "TYPE1, TYPE1, TYPE2, TYPE2, TYPE3, TYPE3, TYPE4, TYPE4";

and I want to manipulate this string and make it as follows:-

string mystring = "TYPE1,TYPE2,TYPE3,TYPE4";

ie I want to just remove all the duplicates in it, how should I do it?

Please help. Thanks.

Answer 1

Well, here's a LINQ approach:

string deduped = string.Join(",", original.Split(',')
                                          .Select(x => x.Trim())
                                          .Distinct());

Note that I'm using Trim because your original string has a space before each item, but the result doesn't.

Distinct() doesn't actually guarantee that ordering will be preserved, but the current implementation does so, and that's also the most natural implementation. I find it hard to imagine that it will change.

If you're using .NET 3.5, you'll need a call to .ToArray() after Distinct() as there are fewer string.Join overloads before .NET 4.

Answer 2

You can do the following:

var parts = mystring.Split(',').Select(s => s.Trim()).Distinct().ToList();
string newString = String.Join(",", parts);