Functions
Function is a block of code which has a name.Each function has a unique name.They are the building blocks of c programs.Functions perform certain tasks repeatedly.Functions provide structured programming approach.
Structure
prototype;
main();
{
function call;
body of program
}
definition
Function consists of two parts
First line of function definition is known as function header.
Syntax
Return-type function name (parameter) ;
{
statement(s);
}
Function BodyThe statements or set of statements which are executed inside the function is known as function body.Body of function appears after function header.
Function Declaration/PrototypeFunction prototype provides information to compiler about the structure of the function to be used in the program.Function prototype ends with semicolon.
Syntax
Return-type function name (parameter) ;
Function Call
A statement that activates a function is known as function call.It is used to invite or call a piece of code or statement. In this case control jumps from main program to that piece of code and then returns back to main program.
Example
#include<stdio.h>
#include<conio.h>
void display ();
main ()
{
clrscr();
display();
getch();
}
void display (void)
{
printf("HELLO WORLD");
}Advantages of using functions
Structure
prototype;
main();
{
function call;
body of program
}
definition
Function consists of two parts
- Function header
- Function body
First line of function definition is known as function header.
Syntax
Return-type function name (parameter) ;
{
statement(s);
}
Function BodyThe statements or set of statements which are executed inside the function is known as function body.Body of function appears after function header.
Function Declaration/PrototypeFunction prototype provides information to compiler about the structure of the function to be used in the program.Function prototype ends with semicolon.
Syntax
Return-type function name (parameter) ;
Function Call
A statement that activates a function is known as function call.It is used to invite or call a piece of code or statement. In this case control jumps from main program to that piece of code and then returns back to main program.
Example
#include<stdio.h>
#include<conio.h>
void display ();
main ()
{
clrscr();
display();
getch();
}
void display (void)
{
printf("HELLO WORLD");
}Advantages of using functions
- Easier to code
- Easier to modify
- Easier to maintain and debug
- Reusability
- less programming time
User Define function
The function written by programmer is known as user defined function.
Built in Function
The function which is a part of language is known as built in function or library function.These functions are stored in header files.They make programming easier and faster.
The function written by programmer is known as user defined function.
Built in Function
The function which is a part of language is known as built in function or library function.These functions are stored in header files.They make programming easier and faster.