c#-6.0

After seeing a similar question , I was wondering if the following expression ... if (attribute != null && attribute.Description == input) ... would behave (almost) identical, to following null-propagation variant? if (attribute?.Description == input) So far, I could determine only following (somehow minor) differences: not possible in case input is of non-nullable type in case input would be itself null , behavior would be altered Am I missing something? or are there other differences in behavior ? EDIT: in the end, the only fail-safe alternative I've found for the first snippet, would be: if

I'm pretty sure there's an example of this somewhere on here, I just can't find it as I don't know the exact terms. So please, be kind. The problem should be a simple one: I have an Azure SQL database, somewhat badly designed (ie missing foreign keys and such). As I cannot redesign the database at this point, I have to handle relations manually via queries. As the database is also the bottleneck of our software, I must try and complete queries with as little database hits as possible. I have entities A, B, C and D. An entity A has several entities B (connected with an unregistered foreign key)

This question already has an answer here: How to use the ternary operator inside an interpolated string? 1 answer Why can't I use the inline conditional-operator inside a c#-6 string interpolation, without encompassing it within brackets? and the errors: As you can see, it appears the parser is having a hard time. Is this a bug, or a feature of the string interpolation mechanism? From MSDN (emphasis mine): $"{person.Name, 20} is {person.Age:D3} year {(p.Age == 1 ? "" : "s")} old." You do not need to quote the quotation characters within the contained interpolation expressions because

Introduction Consider this simple (and bad) C# class: using System; namespace N { static class C { static void M(DateTime d) { if (d == null) Console.WriteLine("Yes"); else Console.WriteLine("No"); } static void L(object o) { if (o is Nullable) Console.WriteLine("Yes"); else Console.WriteLine("No"); } } } Both methods M and L have serious issues. In M , we ask if a value of the non-nullable struct DateTime is equal to null via the lifted == operator (which exists since DateTime overloads operator == ). This is always falls, and the compiler can tell at compile-time, so we have a branch ( "Yes"

In C# 6.0 you can write this: var instance = default(object); var type = typeof(object); They have the same result of: var instance = default(System.Object); var type = typeof(System.Object); But you can't write this: var name = nameof(object); It generates the following error: Invalid expression term 'object'. But you can still write this: var name = nameof(System.Object); Why nameof(object) does not compile? The difference is that object is a synonym for the class Object and nameof() doesn't work on synonyms. Same applies to nameof(int) vs nameof(Int32) 来源： https://stackoverflow.com

In the example below, Resharper shows "C# Experimental language feature" tooltip on the first curly bracket. I've checked the new features of C# 6.0 but didn't come across a similar one. What is the referred experimental feature? class Class1 { { // <= C# Experimental language feature } } Note: It is an error for .Net Framework 4.5 compiler. "Invalid token '{' in class, struct, or interface member declaration" This was for Primary Constructors , a feature which has now been cut from C#6 . On November 12, 2014 Microsoft announced the release of Visual Studio 2015 on the day of Visual Studio

We've recently moved from VS2013 to VS2017 in our company. After the upgrade our codebase would no longer build. We would get the following error: The call is ambiguous between the following methods or properties: 'IRepository<T>.Get(object, params Expression<Func<T, object>>[])' and 'IRepository<T>.Get(object, params string[])' Here is the call itself: this.mainRepository.Get(newEntity.Id); ...and the interface definition: public interface IRepository<T> where T : class { T Get(object id, params Expression<Func<T, object>>[] includeExprs); T Get(object id, params string[] includeExprs); } I

I am trying to get the name of a method on a generic interface. I would expect this to work as the type part would be a valid typeof: //This does not compile nameof(IGenericInterface<>.Method) //This would compile typeof(IGenericInterface<>) I think this should be valid C# 6 or am I missing something or is their a better way to do this. I don't want to use a string for the Method name as if method is renamed code would break without any build time errors. This is expected. According to the documentation , your expression is disallowed, because it refers to an unbound generic type: Because the