The conditional directives are meant to control the compilation process. By using them we may conditionally include certain statements of the program for compilation. If the condition is not met the statements are not included. These directives also help us not to include duplicate files in the program and cause error. For example, see the following code: [Read more…] about Conditional Directives in C

A macro may be used in the definition of another macro as illustrated below. [Read more…] about Nesting of Macros in C

Macros may also be created by #define. Here the identifier can have parameters but types of parameters are not mentioned. [Read more…] about Preprocessor Directive #define

The token # single in its own line is null directive. It is simply neglected by compiler. Thus, if the code is simply as given below, it is neglected by the compiler. [Read more…] about Preprocessor operator ##.

The directive #define is used to create symbolic constants and macros (small function type entities). The directive #define may be used in the following manner: [Read more…] about #define and #undef preprocessor directives