The C preprocessor provides for conditional compilation in instances where large areas of text are ignored and stripped out, regardless of whether a given preprocessor constant was defined. For example:

 #if defined(XYZ)    //code part 1#else     //code part 2#endif

Although this functionality is not directly available in Java, we can achieve the same as follows:

Step 1: Define an Interface:

 interface ABC{    public static final boolean XYZ= true;}

Step 2: Write the conditional statement as usual:

  if (ABC.XYZ)     {     // Code part 1     } else     {     // Code part 2     }

The Java compiler is smart and completely strips the code of the appropriate conditional branch.