Function in C Language

Function in C

Function:-

The fundamental component of a C program that facilitates modularity and promotes code reusability is the function. Functions are employed to execute specific tasks, and they play a crucial role in enabling code reuse: by defining the code once, it can be utilized multiple times.

• A function carries out some specific well defined tasks.
• 
  
• A function will carry out its intended contains whenever it access or called.
• 
  
• Same function can be access from several different places within a program.
• 
  
• A function will process information passed in it from the calling portion.

syntax:-

return type function_name(arguement)

{

//-----

//-----

}

return (-);

syntax of a function for designing of format like (-).

    (------------------------)

draw();

draw(){ printf("\n ----------------------------");}

A- function with no arguement and no return.

sum(); / sum(){}

B- function with arguement and no return.

sum(a,b); / sum(int x, int y){z=x+y;}

C- function with arguement and return.

c=sum(a,b); / sum(int x, int y){ z=x+y; return(z);}

Need of function for repetitive task.

#include<stdio.h>

#include<conio.h>
main()
{
clrscr();
printf("\n --------------------");
printf("\n Employee Details");
printf("\n --------------------");
printf("\n Name Age Salary");
printf("\n Amit 20 15000");
printf("\n Sumit 22 20000");
printf("\n --------------------");
printf("\n Devloped by");
printf("\n Pankaj Kumar Dubey");
printf("\n --------------------");
getch();
}

Function with No argument No return.

This program print dashline where it is called.

#include<stdio.h>

#include<conio.h>

main()

{

clrscr();

dashline(); // function call shows dashline

printf("\n Employee Detail");

dashline(); //function call shows dashline

printf("\n Name Age Salary");

dashline(); //function call shows dashline

printf("\n Amit 20 15000");

printf("\n Sumit 22 22000");

dashline(); //function call shows dashline

printf("\n Developed by");

printf("\n Pankaj Kumar Dubey");

dashline(); //function call shows dashline

getch();

}

//function definition.

dashline()

{

printf("\n ----------------------------");

}

Function with argument No return.

#include<stdio.h>

#include<conio.h>
main()
{
clrscr();
dashline(*); // function call shows * line.
printf("\n Employee Detail");
dashline(#); // function call shows # line.
printf("\n Name Age Salary");
dashline($); // function call shows $ line.
printf("\n Amit 20 15000");
printf("\n Sumit 22 22000");
dashline($); // function call shows # line.
printf("\n Developed by");
printf("\n Pankaj Kumar Dubey");
dashline(*); // function call shows * line.
getch();
}

//function definition - whatever character send to at 'p' i.e. printed from where it is called like that '*', '#', '$'.

dashline(char p)
{
int i;
printf("\n");
for(i=0;i<=30;i++)
{
printf("%c",p);
}
}

Function with No argument No return.

//This program has a function name sum() that demands 2 input and calculate their addition where it is called.

// this function demands different-different values every time when it is called.

#include<stdio.h>

#include<conio.h>

main()

{

clrscr();

sum();         //function with no argument i.e. sum() called here.

getch();

}

//function definition.

sum()

{

int a,b,c;

printf("\n Enter the value of a ");

scanf("%d",&a);

printf("\n Enter the value of b ");

scanf("%d",&b);

c=a+b;

printf("\n The value of sum is %d",c);

}

Function with argument No return.

//This program has a function with argument i.e. sum(a,b) used to pass the values only for calculation.

//this function returns same value every time because the values are taken in main() function before called to sum(a,b).

#include<stdio.h>

#include<conio.h>

main()

{

clrscr();

int a,b;

printf("\n Enter the value of a ");

scanf("%d",&a);

printf("\n Enter the value of b ");

scanf("%d",&b);

sum(a,b); //function with argument i.e. sum(a,b) called.

getch();

}

//function definition.

sum(int x, int y)

{

int z;

z=x+y;

printf("\n The value of sum is %d",z);

}

//Function with argument with return.

//This program has a function sum(a,b) used to pass the values only for calculation and return is used here.

//this function returns same value every time because the values are taken in main() function before called to sum(a,b).

#include<stdio.h>

#include<conio.h>

main()

{

int a,b,c;

clrscr();

printf("\n Enter the value of a ");

scanf("%d",&a);

printf("\n Enter the value of b ");

scanf("%d",&b);

c=sum(a,b); // The value is returned in variable c.

printf("\n The value of sum is %d",c);

getch();

}

//function definition.

sum(int x, int y)

{

int z;

z=x+y;

return(z);

}