This technique is called preprocessor and the process is called preprocessing. File inclusive directives file inclusive directories are used to include user define header file inside c program. Learn competitive and technical aptitude c programming mcq questions and answers on c preprocessor with easy and logical explanations. So the code is converted to following after the preprocessing step. Covers topics like introduction to preprocessor directives, macro expansion, file inclusion, summary of preprocessor directives etc. C program to find sum of two numbers using macro codeforwin. It instructs the c compiler to do some specific required preprocessing before the compilation process when we compile a c program, c preprocessor processes the statements which are associated with it and expand them to make the code for further compilation. Macro taking argument in c argumented macro preprocessor inc programming. Preprocessors are an important part of the c program, without it, we cant run any program. The preprocessor determines if the provided macro does not exist before including the subsequent code in the compilation process. The c preprocess or is not a part of the compiler, but is a separate step in the compilation process. Before a c program is compiled in a compiler, source code is processed by a program called preprocessor. When we try to compile a program, preprocessor commands are executed first and then the program gets compiled.
The preprocessor does not know anything about keywords. These lines are not program statements but directives for the preprocessor. C preprocessor directives tutorial to learn c preprocessor directives in simple, easy and step by step way with syntax, examples and notes. The preprocessor provides several other facilities which will be described here.
Preprocessor programs provide preprocessors directives which tell the compiler to preprocess the source code before compiling. C preprocessor with programming examples for beginners and professionals covering concepts, control statements, c array, c strings and more. Beginners should learn this concept to master c programming. We tried to understand preprocessors in c through a realtime example. Preprocessor directives c programming developer insider. How to write a program to replace macros in c quora. The c prep roc essor is a macro pr eprocessor allow s you to defi ne macros tha t trans f orms you r program before it is compiled. The c preprocessor offers the following operators to help create macros. It is particularly useful for selecting machine dependent pieces of code for different computer types, allowing a single program to be compiled and run on several. Preprocessor directives in c programming language are used to define and replace tokens in the text and also used to insert the contents of other files into the source file. A macro is a fragment of code that is given a name.
This can be useful if you wish to hide a keyword such as const from an older compiler that does not understand it. Here, we covered details like, what are preprocessor directives, how do preprocessors work and what are its different types. The macro continuation operator \ is used to continue a macro that is too long for a single line. A macro is a name given to a block of c statements as a pre processor directive. A program is converted to executable using following steps 1 preprocessing 2 c code to object code conversion 3 linking the first step processes macros.
Web design html tutorials online html, css and js editor css tutorials bootstrap 4 tutorials. C preprocessor c programming mcq questions and answers. Difference between macro and function in c programming. The c preprocessor modifies a source code file before handing it over to the compiler. The c preprocess or i s a mac ro processor that is used automatically b y th e c compiler to transfo rm your pro gram before actual compilati on proproce ssor direcives are executed before compilation. This video contain lecture for topic preprocessor directive of c language. It expands macros in parts of some directives that arent skipped as part of a conditional compilation. How to define, undefine and redefine a macro in c programming. This macro is used to include a header file into the source file. C preprocessors c preprocessor is a program invoked by the c compiler that modify the source code before the actual composition takes place. C preprocessor for c programming mcq practice questions.
Introduction to c preprocessor in c compilation model and processes, the c source code is passed to a preprocessor before being transferred to the compiler. The preprocessor selects one of the given occurrences of. A variadic macro is a feature of the preprocessor whereby a macro is declared to accept a varying number of arguments similar to a variadic function. The preprocessor provides the ability for the inclusion of header files, macro expansions, conditional compilation, and line control.
Below is the list of preprocessor directives that c programming language. File inclusive directives c preprocessor directives c. It is call e d a m acro processor because it allows yo u to d ef ine ma cros, which are brief abbreviations for longer constructs. How does the c preprocessor handle circular dependencies. Preprocessor in c pre processor is a program which will executed automatically before passing the source program to compiler.
The preprocessor provides the ability for the inclusion of h e ader f iles, macro expansions, conditional compilation, and lin e contro l in many c implementati ons, it is a sep arate program invoked by the compiler as the first part of translation. The advantage of using macro is the execution speed of the program fragment. The c preprocessor is a tool which filters your source code before it is compiled. Being a pre processor, the block of code is communicated to the compiler before entering into the actual coding main function. Klick2learn complete training solution 45,650 views. It is called a macro processor because it allows you to define macros, which are brief abbreviations for longer constructs. In simple terms, a c preproce ssor is just a text substitution tool and it instructs the compiler to do requi red preproces sing before the actual compilation.
File inclusive directory checks included header file inside same directory if path is not mentioned. Here you will need to provide assembly program containing macro as input in macin. The c preprocessor the c preprocessor is a macro processor that is used automatically by the c compiler to transform your program before actual compilation. Nested preprocessor macro directive having arguments in c programming. Learn the importance of preprocessors in c is it worth. A c preprocessor is a statement substitution text substitution in c programming language. Preprocessor directives in c language, macro substitution. Here, when we use c in our program, it is replaced with 299792458.