The List<string> has ("ABC","","DEF","","XYZ"), how can I get the string "ABC::DEF::XYZ" out of the List in C#?
List<string> strings = new List<string> {"ABC","","DEF","","XYZ"};
string joined = string.Join("::", strings.ToArray());
Console.WriteLine(joined);
gives ABC::::DEF::::XYZ, not ABC::DEF::XYZ, how can one skip the empty strings ("") in a list?
You can do:
List<string> strings = ...
string joined = string.Join(":", strings.ToArray());
In .NET 4.0, you can leave out the ToArray() call.
EDIT: Based on your update that indicates that you want to skip empty strings and use two colons as the delimiter, you can do:
// Use !string.IsNullOrEmpty or !string.IsNullOrWhiteSpace if more appropriate.
string[] filtered = list.Where(s => s != string.Empty)
.ToArray();
string joined = string.Join("::", filtered);
string result = string.Join("::", list.Where(s => !string.IsNullOrEmpty(s)).ToArray());
string.Join("::", strings.Where(item=>!string.IsNullOrEmpty(item)).ToArray());
string.Join( ":", list ) in .NET 4.0. If you are using 3.5 or earlier, string.Join( ":", list.ToArray() )
List<T> has had a ToArray method in it's signature. So as long as you're not using .NET 1.1, you should be ok.You should look at String.Join(), example String.Join(":",list.ToArray());
Using string.Join with ToArray would work.
As Ani said, if you're on .NET 4.0, you could leave out the ToArray.
If you're not on .NET 4.0 but you don't want the overhead of the ToArray call, you could write a method to create a StringBuilder, append every item in the List<string> plus your delimiter (skipping the delimiter after the last item), and return the result of ToString at the end.
ToArray is more significant than the overhead of a StringBuilder and then iterating through the collection?I think you can have a look at The suggested method
post this you can simply do string.Join(",", strings.ToArray())
(replace the empty strings with ::)
