Why use const in C#?

Question

What's the point of ever using const?
It is more restrictive than static readonly:

across assemblies, changes to a constin a dependency won't be reflected in its consumers
you can only use const for certain primitive types

with both these restrictions in mind, perhaps among others I am not aware of,  why ever use const?
Why not always use static readonly to maintain consistency of style?

Sebastian Redl · Answer

Things declared const are true compile-time constants, and thus may occur in constant-expressions. This means you can use them in the following contexts, where static readonly variables may not appear[1]:

Values of other constants: const int OTHER = N;
Explicit values of enum members: enum Foo { Bar = N }
Default arguments: void Fn(int i = N)
case labels: case N: and goto case N;
Attribute values: [Value(N)]
(rather irrelevant) array creation with initializers: new int[N] { 1, 2, 3 }

[1] https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/language-specification/expressions#constant-expressions

Why use const in C#?

One Answer

Add your own answers!

Ask a Question