Explain #define preprocessor directive

[Javiier]

I am covering a topic called Preprocessor Directive in Csharp. I have learnt the #if preprocessor directive, but I am not able to grasp what is the #define preprocessor directive. How is it actually used? I have been using Java for along time but I am new to Csharp. I am totally confused over this topic. Reply fast.

[Praetor]

There is a huge similarity between C preprocessor and C sharp preprocessor. Infact the C sharp preprocessor are said to be derived from C programming language. the #define will allow you to define a symbol to be used as the #if directive's expression.
Syntax:

#define symbol

[Zecho]

I am also a new programmer to Csharp programming. I find this very interesting and easy to learn and develop application for .NET Framework. This example will illustrate the use of #define preprocessor directive in C sharp.

#define Temp 
 
using System; 
 
public class A
{ 
  public static void Main()
  { 
    #if Temp 
    Console.WriteLine("From #IF"); 
    #endif 
    Console.WriteLine()
    Console.WriteLine("Outside #IF"); 
  } 
}

[opaper]

C# preprocessor directives have alot of resemblence to the C preprocessor directives. The #define directive lets the programmer to define symbols which control the compilation of the C# code. #define preprocessor directive of C sharp defines a symbol whereas the #undef preprocessor directive of C sharp undefines a symbol.