Is it possible for String.split() to return tuple?

Question

I have string which I need to split() and assign it's value into two variables. Is it possible for split() to return tuple instead of string[] so I can do something like:

String myString = "hello=world" value, id = myString.Split('='); 

I'm looking for some elegant solution.

Answer 1

If you can use C# 7 - you can use tuple deconstruction. If type has static or extension method named Deconstruct with appropriate signature - this type can be deconstructed. So you can have extension method like this:

public static class Extensions {     public static void Deconstruct<T>(this IList<T> list, out T first, out IList<T> rest) {          first = list.Count > 0 ? list[0] : default(T); // or throw         rest = list.Skip(1).ToList();     }      public static void Deconstruct<T>(this IList<T> list, out T first, out T second, out IList<T> rest) {         first = list.Count > 0 ? list[0] : default(T); // or throw         second = list.Count > 1 ? list[1] : default(T); // or throw         rest = list.Skip(2).ToList();     } } 

And then you can deconstruct string array (which implements IList<string>) with this syntax (you might need to add appropriate using so that extension method above is reachable):

var line = "a=b"; var (first, second, _) = line.Split('='); Console.WriteLine(first); // "a" Console.WriteLine(second); // "b" 

or

var line = "a=b"; var (first, (second, _)) = line.Split('='); Console.WriteLine(first); // "a" Console.WriteLine(second); // "b" 

Which is quite close to what you need.

With just first extension method above (which deconstructs to first element and the rest) you can deconstruct to arbitrary length:

var (first, (second, _)) = line.Split('='); var (first, (second, (third,  _))) = line.Split('='); var (first, rest) = line.Split('='); // etc 

Second extension method is needed only if you want a little bit more convenient syntax for deconstruction of first 2 values (var (first, second, rest) instead of var (first, (second, rest)))