Demonstrate #elif : Elif : Preprocessing Directives C# Examples

The #else directive establishes an alternative if #if fails.
#else marks both the end of the #if block and the beginning of the #else block.
The #elif directive means "else if".
The #elif directive establishes an if-else-if chain for multiple compilation options.
#elif is followed by a symbol expression.
There can be only one #endif associated with any #if.
If the expression is true, that block of code is compiled, and no other #elif expressions are tested.

The general form for #elif is




    
#if  symbol-expression  
            statement  sequence  
        #elif  symbol-expression  
            statement  sequence  
        #elif  symbol-expression
            statement  sequence  
        #elif  symbol-expression
            statement  sequence  
        #elif  symbol-expression  
        .
        .
        .
        #endif
    
   
  
   





    
#define  AAA  
#define  RELEASE  
  
using  System;  
  
class  MainClass  {  
    public  static  void  Main()  {  
          
        #if  AAA  
            Console.WriteLine("Compiled  for  AAA  version.");  
        #elif  RELEASE  
            Console.WriteLine("Compiled  for  release.");  
        #else  
            Console.WriteLine("Compiled  for  internal  testing.");  
        #endif  
  
        #if  BBB  &&  !RELEASE  
              Console.WriteLine("BBB  version.");  
        #endif  
      
        Console.WriteLine("This  is  in  all  versions.");  
    }  
}