Are global constants possible?

Question

Is it possible to declare global constants? That is, constants that are available in all classes? When I try to declare a constant outside of a class, as I do with an enum, I get a parsing error.

I've been using enums this way for a while, but enums are restricted to integers, and I'd like to use easy-to-use words instead of float values.

Example; I'd like the following to be available in any class:

const float fast   = 1.5f;
const float normal = 1f; 
const float slow   = .75f;

I know i can work around this by creating an enum (Speed) for the speed names, then creating a static method SpeedNum() that reads enum Speed and returns an associated value, but it requires so much extra writing each time and I was hoping for something more elegant:

Ex:

public double function SpeedNum(Speed speed) 
{
    switch (speed)
    {
        case speed.fast:   return 1.5;
        case speed.normal: return 1f;
        case speed.slow:   return .75f;
    }
}

Answer 1

Create a static class e.g. called Constants containing the constants and access them using Constants.MyConstant.

public static class Constants
{
  public const string MyConstant = "Hello world";
  public const int TheAnswer = 42;
}

class Foo
{
  // ...

  private string DoStuff()
  {
    return Constants.MyConstant;
  }
}

To answer your implied question: You cannot declare constants outside of a class.

Answer 2

If you're targeting C# version 6 or higher, and you don't want to use the traditional "static_class_name.Thing", you may use using static, introduced in C# 6.

// File 1
public static class Globals
{
    public const string bobsName = "bob!";
}

// File 2
using System;
using static Globals;

class BobFinder
{
    void Run() => Console.WriteLine(bobsName);
}

Syntactical sugar. But I find it nifty.