Compile Conditional, How we write it?

 Reference to compile conditional, How we write it and what is syntex of it? And also provide the code syntex please

The general idea behind conditional compilation is that a piece of code can be selectively compiled, depending upon whether a specific value has been #defined, or not. Reasons for doing this vary, but the main ones seem to be:

Platform specific constraints
Debug builds
Performance issues
You can find more about conditional compiling in the links provided below:



http://ee.hawaii.edu/~tep/EE160/Book/chap3/subsection2.1.3.4.html
http://publib.boulder.ibm.com/infocenter/iadthelp/v7r0/index.jsp?topic=/com.ibm.etools.iseries.langref.doc/ilcrefer21.htm
http://msdn.microsoft.com/en-us/library/ew2hz0yd(v=vs.80).aspx