Lecture 17 – Functions (continued)

Let’s see how we can write a function which takes no argument but returns a value.

Type 2 – Functions that take NO argument and returns A value

I would write a function which would

1.       Ask the user to input a number

2.       Calculate its square

3.       Return the calculated value to main function

4.       Main function will display calculated result

 

#include <stdio.h>

#include <conio.h>

 

void square()

{

int number;

printf(“\nPlease enter a number :”);

Output There would be no output as it has a syntax error. The error is LVALUE REQUIRED

scanf(“%d”, &number);

number = number * number;

return number;

}

void main()

{

clrscr();                 // Function Call

square();             // Function Call to my function Square

getch();                                // Function Call

}

Example 33 - Using parameter less function

If you are using a function which returns a value then you need to have a placeholder/a variable to receive value from the called function. Consider a modified example.

#include <stdio.h>

#include <conio.h>

 

 

void square()

{

int number;

printf(“\nPlease enter a number :”);

Output Please enter a number: 5 The square is 25

scanf(“%d”, &number);

number = number * number;

return number;

}

void main()

{

int result;

clrscr();                 // Function Call

result  = square();            // Function Call to my function Square, and capturing the result

printf(”\nThe square is %d”, result);

getch();                                // Function Call

}

Example 34 - Catching returned value from a function call