Macro and Preprocessor in c programming
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The document discusses C preprocessors and macros. It explains that the preprocessor is executed before compilation and includes directives like #include to add header files. Macros allow small pieces of code to be given a name and replaced wherever that name is used. Simple macros perform text substitution without parameters. Parameterized macros can take parameters, similar to functions, and are illustrated with a macro to calculate the square of a number.
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Macro and Preprocessor in c programming
- 1. C Preprocessors Macro Simple Parameterized By Asst. Prof. Sonali Gholve- Doifode
- 2. Preprocessor C Source code Preprocessor Compiler • Preprocessor is a collection of special statements, called directives, that are executed at the beginning of the compilation process. • # • Eg. #include => include the header file into the program. • #include<stdio.h>, #include<string.h>
- 3. Macro • What is macro? • Macro is a small part of a code that is given a name. Whenever the name is used, it is replaced by the contents of the macro. • you can define macro in C using #define preprocessor directive • Simple macro substitution • Parameterized macro/function like macro
- 4. Simple macro substitution • It is used to simple replacement of identifier by string. • Eg. To calculate area of circle using macro #include<stdio.h> #define PI 3.14 int main() { float rad, area; printf(“ Enter the radius”); scanf(“%f”,&rad); area=PI *rad*rad; printf(“Area of circle=%f”, area); return 0; }
- 5. Parameterized macro/Function like macro substitution • Macro that takes the parameter. • Eg. To calculate square of number using macro #include<stdio.h> #define square (x) ((x)*x) int main() { int p; p=square(5); printf(“n Square of 5 is=%d”, p); return 0; }