C program to make a function return multiple values

C program to make a function return multiple values using call by reference

In c programming, function can return a single value at a time, lets see how we can make function to return multiple values through below program.

Using call by reference, we can make function return more than one values at a time which is not possible ordinarily.

Call by reference means passing variable addresses to the function instead of values.

#include<stdio.h>                                                              
                                                                                
void computecircleparams(int, float*, float*);                                  
void main()                                                                     
{                                                                               
  int radius;                                                                   
  float area, perimeter;                                                        
  printf("\nEnter radius of a circle: ");                                       
  scanf("%d", &radius);                                                         
  computecircleparams(radius, &area, &perimeter);                               
  printf("\nCircle Area: %f", area);                                            
  printf("\nCircle Perimeter: %f", perimeter);                                  
}                                                                               
                                                                                
void computecircleparams(int cradius, float *carea, float *cperimeter)          
{                                                                               
  *carea = 3.14 * cradius * cradius;                                            
  *cperimeter = 2 * 3.14 * cradius;                                             
}                                                                                   

Output:

$ cc multiple-return-values.c
$ ./a.out 

Enter radius of a circle: 10

Circle Area: 314.000000
Circle Perimeter: 62.799999

This c program passing address to a function for float variable area and perimeter.

computecircleparams function computes the area and perimeter using radius passed to this function, and updates the reference of area and perimeter variables with computed value using area and perimeter formula's.