How to declare a local constant in C#?

Question

How to declare a local constant in C# ?

Like in Java, you can do the following :

public void f(){   final int n = getNum(); // n declared constant } 

How to do the same in C# ? I tried with readonly and const but none seems to work.

Any help would be greatly appreciated.

Thanks.

Answer 1

In C#, you cannot create a constant that is retrieved from a method.

Edit: dead link http://msdn.microsoft.com/en-us/library/e6w8fe1b(VS.71).aspx

This doc should help: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/const

A constant expression is an expression that can be fully evaluated at compile time.

Answer 2

Declare your local variable as an iteration variable. Iteration variables are readonly (You didn't ask for a pretty solution).

public void f()  {   foreach (int n in new int[] { getNum() }) // n declared constant   {     n = 3; // won't compile: "error CS1656: Cannot assign to 'n' because it is a 'foreach iteration variable'"   } }