Using the Integer class here is probably what you want to do. The overhead associated with the object is most likely (though not necessarily) trivial to your applications overall responsiveness and performance.
I said earlier that (1) this is a compiler bug and (2) it is a new one. The first statement was accurate; the second was me getting confused in my haste to get to the bus on time. (The bug I was thinking of that is new to me is a much more complicated bug … Read more
The C# compiler provides you with a bit of sugar so you really are doing this: Nullable<bool> b = new Nullable<bool>(); Here is the syntactic sugar bool? b = null; if (b ?? false) { b = true; }
Is there a performance benefit to one way over the other? No. They both compile to the exact same IL. The cast is syntactic sugar for the Value property. This code: int? x = null; Console.WriteLine(x.Value); Console.WriteLine((int)x); compiles to these IL instructions, ignoring nops: (you can test this yourself using ildasm, ILSpy, DotPeek, etc.) // … Read more
In my case, I ran into this problem with Visual Studio 2022 when I changed the target framework from .NET Standard 2.1 to .NET Standard 2.0. I solved my problem by removing <Nullable>enable</Nullable> in the .csproj file and restarting Visual Studio. Original .csproj file: <PropertyGroup> <TargetFramework>netstandard2.1</TargetFramework> <Nullable>enable</Nullable> </PropertyGroup> New .csproj file: <PropertyGroup> <TargetFramework>netstandard2.0</TargetFramework> </PropertyGroup>
I agree with Stuart Marks that list == null ? Stream.empty() : list.stream() is the right way to do this (see his answer), or at least the right way to do this pre-Java 9 (see edit below), but I’ll leave this answer up to demonstrate usage of the Optional API. <T> Stream<T> getStream(List<T> list) { … Read more
For C# 7 In C# 7, throw becomes an expression, so it’s fine to use exactly the code described in the question. For C# 6 and earlier You can’t do that directly in C# 6 and earlier – the second operand of ?? needs to be an expression, not a throw statement. There are a … Read more
The type pattern in its various forms: x is T y, case T y etc, always fails to match when x is null. This is because null doesn’t have a type, so asking “is this null of this type?” is a meaningless question. Therefore t is int? i or t is Nullable<int> i makes no … Read more
For empty field you can check for empty values which is zero value which is not nil in case of struct. When storage is allocated for a variable, either through a declaration or a call of new, or when a new value is created, either through a composite literal or a call of make, and … Read more
How about an extension method for your dictionary? public static void AddIfNotNull<T,U>(this Dictionary<T,U> dic, T key, U value) where U : class { if (value != null) { dic.Add(key, value); } } You could then do this: myDictionary.AddIfNotNull(“…”,myObject.whatever);