Manipulate string problem

If I have a string variable with val开发者_运维百科ue 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.

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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.

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You can do the following:

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

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

var split = mystring.Split(',');
var distinct = (from s in split select s).Distinct();

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One liner

string result = string.Join(",", mystring.Split(',').Select(s => s.Trim()).Distinct());

Ordering?

You can as well add OrderBy() in the line to sort your strings if you need to.

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I'd personally go for the Linq option in Jon Skeet's answer, so I've also upvoted that, but just to give you another other option

List<string> parts = new List<String>();
foreach(string split in mystring.Split(','))
    if(!parts.Contains(split))
        parts.Add(split);

string newstr = "";
foreach(string part in parts)
    newstr += part + ",";

This will work in older versions of C# too.