There’s also a DataSetExtension method called “AsEnumerable()” (in System.Data) that takes a DataTable and returns an Enumerable. See the MSDN doc for more details, but it’s basically as easy as: dataTable.AsEnumerable() The downside is that it’s enumerating DataRow, not your custom class. A “Select()” LINQ call could convert the row data, however: private IEnumerable<TankReading> ConvertToTankReadings(DataTable … Read more
Because ForEach(Action) existed before IEnumerable<T> existed. Since it was not added with the other extension methods, one can assume that the C# designers felt it was a bad design and prefer the foreach construct. Edit: If you want you can create your own extension method, it won’t override the one for a List<T> but it … Read more
yourEnumerable.Cast<object>().Count() To the comment about performance: I think this is a good example of premature optimization but here you go: static class EnumerableExtensions { public static int Count(this IEnumerable source) { int res = 0; foreach (var item in source) res++; return res; } }
You want IEnumerable.Any() extension method (.Net Framework 3.5 and above). It avoids counting over the elements.
As already suggested, use yourEnumerable.ToList(). It enumerates through your IEnumerable, storing the contents in a new List. You aren’t necessarily copying an existing list, as your IEnumerable may be generating the elements lazily. This is exactly what the other answers are suggesting, but clearer. Here’s the disassembly so you can be sure: public static List<TSource> … Read more
I am only listing out the equivalents of functions from Enumerable<A>. This is incomplete as of now. I will try to update this later with more. xs.Aggregate(accumFunc) -> xs.reduceLeft(accumFunc) xs.Aggregate(seed, accumFunc) -> xs.foldLeft(seed)(accumFunc) xs.Aggregate(seed, accumFunc, trans) -> trans(xs.foldLeft(seed)(accumFunc)) xs.All(pred) -> xs.forall(pred) xs.Any() -> xs.nonEmpty xs.Any(pred) -> xs.exists(pred) xs.AsEnumerable() -> xs.asTraversable // roughly xs.Average() -> xs.sum … Read more
You have already accepted an answer however,since generic IEnumerable<T> implements the non generic IEnumerable you can just cast to that. // Does write handle null? Might need some sanity aswell. var enumerable = variable as System.Collections.IEnumerable; if (enumerable != null) foreach(var item in enumerable) Write(item); else Write(item);
After discussion with Erik Funkenbusch, which led to looking into the MVC source code, it would appear there are two nicer (correct and idiomatic?) ways to do it. Both involve providing correct html name prefix to the helper, and generate HTML identical to the output of the default EditorFor. I’ll just leave it here for … Read more
In .NET 4 this becomes even easier:- var input = new[] { “a”, “b”, “c”, “d”, “e”, “f” }; var result = input.Zip(input.Skip(1), (a, b) => Tuple.Create(a, b));
Basically the nongeneric interfaces came first, in .NET 1.0 and 1.1. Then when .NET 2.0 came out, the generic equivalents came out. Life would have been a lot simpler if generics had made it into .NET 1.0 🙂 In terms of implementing “only” IEnumerable<T> instead of both – you basically have to implement both, and … Read more