Compiler Details

• File with .m extension indicate file holds Objective C code.

• File with .c extension indicate file holds 'C' code

• File with .cpp extension indicate file holds 'C++' code

• All this compiling is handled by GNU Compiler Collection also known as GCC.

• Like 'C' language include directive 'Objective C' uses import directive. Import directive insures header is imported only once, no matter how many times header is imported at different levels.