Explanation
D: Also, it's worth pointing out that you can use [Conditional("DEBUG")] attribute on methods that return void to have them only executed if a certain symbol is defined. The compiler would remove all calls to those methods if the symbol is not defined:
[Conditional("DEBUG")]
void PrintLog() {
Console.WriteLine("Debug info");
}
void Test() {
PrintLog();
}
G: When the C# compiler encounters an directive, followed eventually by an #endif directive, it will compile the code between the directives only if the specified symbol is defined. Unlike C and C++, you cannot assign a numeric value to a symbol; the #if statement in C# is Boolean and only tests whether the symbol has been defined or not. For example,
#define DEBUG
#if DEBUG
Console.WriteLine("Debug version");
#endif
Reference: http://stackoverflow.com/questions/2104099/c-sharp-if-then-directives-for-debug-vs-release