Question

public static int Test(int n)
{
  if (n < 0) return 1;
  if (n == 0) return 2;
  if (n > 0) return 3;
}

Compiler (Visual Studio 2010, C# 4.0) says “Not all code paths return a value”. Why?

Answer 1

The compiler isn’t looking at your conditions. Even though you are correct that at least one of your if-blocks will run, you still need to refactor to something like this:

if (n < 0)
    return 1;
else if (n == 0)
    return 2;
else
    return 3;