Question

I wrote a program which computes the area and perimeter of a square, circle, or rectangle. As you will see in my main function, there is a for loop in which the user is supposed to be able repeat the program until they enter "q" to quit. However, my program runs through one time, the prompt appears again, but then it terminates before the user is allowed to respond to the prompt again. I'm not able to debug why this is happening,

/*This program computes the area and perimeter of a square, rectangle, or circle*/

#include <stdio.h>
#include <math.h>

#define PI 3.14159

//Struct types defining components needed to represent each shape
typedef struct {
   double area, circumference, radius;
} circle_t;

typedef struct {
   double area, perimeter, width, height;
} rectangle_t;

typedef struct {
   double area, perimeter, side;
} square_t;

//Union type that can be interpreted in a different way for each shape
typedef union {
   circle_t circle;
   rectangle_t rectangle;
   square_t square;
} figure_data_t;

//Struct type containing union: select the figure you want, and the necessary components of that figure
typedef struct {
   char shape;
   figure_data_t fig;
} figure_t;

//Function declarations
figure_t get_figure_dimensions(void);
figure_t compute_area(figure_t object);
figure_t compute_perim(figure_t object);
void print_figure(figure_t object);

//Main Function
int main(int argc, char* argv[])
{
   figure_t onefig;

   printf("Area and Perimeter Computation Program\n");

   for (onefig = get_figure_dimensions();
       onefig.shape != 'Q';
       onefig = get_figure_dimensions())
   {
       onefig = compute_area(onefig);
       onefig = compute_perim(onefig);
       print_figure(onefig);
   }

   return 0;
}

//////////////////

//Function Definitions//
/*Prompts for and stores the dimension data necessary to compute a figure's area and perimeter.
Figure returned contains a "Q" in the shape component when signaling end of data.*/
figure_t get_figure_dimensions(void)
{
   figure_t object;
   printf("Enter a letter to indicate the object shape or Q to quit.\n");
   printf("C (circle), R (rectangle), or S (square): ");
   object.shape = getchar();

   switch (object.shape)
   {
   case 'C':
   case 'c':
       printf("Enter radius: ");
       scanf("%lf", &object.fig.circle.radius);
       break;
   case 'R':
   case 'r':
       printf("Enter Height: ");
       scanf("%lf", &object.fig.rectangle.height);
       printf("Enter width: ");
       scanf("%lf", &object.fig.rectangle.width);
       break;
   case 'S':
   case 's':
       printf("Enter length of a side: ");
       scanf("%lf", &object.fig.square.side);
       break;
   default: //Error is treated as a QUIT
       object.shape = 'Q';
   }
   return object;
}

/*Computes the area of a figure given relevant dimensions. Returns figure with area component filled.
Pre: value of shape component is one of these letters: CcRrSs
   necessary dimension components have values*/
figure_t compute_area(figure_t object)
{
   switch (object.shape)
   {
   case 'C':
   case 'c':
       object.fig.circle.area = PI * pow(object.fig.circle.radius, 2);
       break;
   case 'R':
   case 'r':
       object.fig.circle.area = object.fig.rectangle.height * object.fig.rectangle.width;
       break;
   case 'S':
   case 's':
       object.fig.square.area = pow(object.fig.square.side, 2);
       break;
   default:
       printf("Error in shape code detected in compute_area\n");
   }
   return object;
}

//The code for the functions below is an assignment
figure_t compute_perim(figure_t object)
{
   switch (object.shape)
   {
   case 'C':
   case 'c':
       object.fig.circle.circumference = 2 * PI * object.fig.circle.radius;
       break;
   case 'R':
   case 'r':
       object.fig.rectangle.perimeter = (2 *object.fig.rectangle.height) + (2 * object.fig.rectangle.width);
       break;
   case 'S':
   case 's':
       object.fig.square.perimeter = 4 * object.fig.square.side;
       break;
   default:
       printf("Error in shape code detected in compute_perim\n");
   }
   return object;
}
void print_figure(figure_t object)
{
   switch (object.shape)
   {
   case 'C':
   case 'c':
       printf("For a circle with a radius of %.2f, the area is %.2f and the circumference is %.2f\n\n",
           object.fig.circle.radius, object.fig.circle.area, object.fig.circle.circumference);
       break;
   case 'R':
   case 'r':
       printf("For a rectangle with a width of %.2f and a height of %.2f,\n",
           object.fig.rectangle.width, object.fig.rectangle.height);
       printf("the area is %.2f and the perimeter is %.2f\n\n",
           object.fig.rectangle.area, object.fig.rectangle.perimeter);
       break;
   case 'S':
   case 's':
       printf("For a square with a side length of %.2f, the area is %.2f and the perimeter is %.2f\n\n",
           object.fig.square.side, object.fig.square.area, object.fig.square.perimeter);
       break;
   default:
       printf("Error in shape code detected in print_figure\n\n");
   }
}

Answer 1

Thanks for the question.

I made 3 changes and its working as expected. ! Attached screenshot. Changes are commented in the code.

Thank You !!
========================================================================================

/*This program computes the area and perimeter of a square, rectangle, or circle*/

#include <stdio.h>
#include <math.h>

#define PI 3.14159

//Struct types defining components needed to represent each shape
typedef struct {
double area, circumference, radius;
} circle_t;

typedef struct {
double area, perimeter, width, height;
} rectangle_t;

typedef struct {
double area, perimeter, side;
} square_t;

//Union type that can be interpreted in a different way for each shape
typedef union {
circle_t circle;
rectangle_t rectangle;
square_t square;
} figure_data_t;

//Struct type containing union: select the figure you want, and the necessary components of that figure
typedef struct {
char shape;
figure_data_t fig;
} figure_t;

//Function declarations
figure_t get_figure_dimensions(void);
figure_t compute_area(figure_t object);
figure_t compute_perim(figure_t object);
void print_figure(figure_t object);

//Main Function
int main(int argc, char* argv[])
{
figure_t onefig;

printf("Area and Perimeter Computation Program\n");
   while(1){ // updated this line
       onefig = get_figure_dimensions();
       if(onefig.shape == 'Q')break;   // updated this line
onefig = compute_area(onefig);
onefig = compute_perim(onefig);
print_figure(onefig);
}

return 0;
}

//////////////////

//Function Definitions//
/*Prompts for and stores the dimension data necessary to compute a figure's area and perimeter.
Figure returned contains a "Q" in the shape component when signaling end of data.*/
figure_t get_figure_dimensions(void)
{
figure_t object;
printf("Enter a letter to indicate the object shape or Q to quit.\n");
printf("C (circle), R (rectangle), or S (square): ");
scanf(" %c",&object.shape); // updated this line

switch (object.shape)
{
case 'C':
case 'c':
printf("Enter radius: ");
scanf("%lf", &object.fig.circle.radius);
break;
case 'R':
case 'r':
printf("Enter Height: ");
scanf("%lf", &object.fig.rectangle.height);
printf("Enter width: ");
scanf("%lf", &object.fig.rectangle.width);
break;
case 'S':
case 's':
printf("Enter length of a side: ");
scanf("%lf", &object.fig.square.side);
break;
default: //Error is treated as a QUIT
object.shape = 'Q';
}
return object;
}

/*Computes the area of a figure given relevant dimensions. Returns figure with area component filled.
Pre: value of shape component is one of these letters: CcRrSs
necessary dimension components have values*/
figure_t compute_area(figure_t object)
{
switch (object.shape)
{
case 'C':
case 'c':
object.fig.circle.area = PI * pow(object.fig.circle.radius, 2);
break;
case 'R':
case 'r':
object.fig.circle.area = object.fig.rectangle.height * object.fig.rectangle.width;
break;
case 'S':
case 's':
object.fig.square.area = pow(object.fig.square.side, 2);
break;
default:
printf("Error in shape code detected in compute_area\n");
}
return object;
}

//The code for the functions below is an assignment
figure_t compute_perim(figure_t object)
{
switch (object.shape)
{
case 'C':
case 'c':
object.fig.circle.circumference = 2 * PI * object.fig.circle.radius;
break;
case 'R':
case 'r':
object.fig.rectangle.perimeter = (2 *object.fig.rectangle.height) + (2 * object.fig.rectangle.width);
break;
case 'S':
case 's':
object.fig.square.perimeter = 4 * object.fig.square.side;
break;
default:
printf("Error in shape code detected in compute_perim\n");
}
return object;
}
void print_figure(figure_t object)
{
switch (object.shape)
{
case 'C':
case 'c':
printf("For a circle with a radius of %.2f, the area is %.2f and the circumference is %.2f\n\n",
object.fig.circle.radius, object.fig.circle.area, object.fig.circle.circumference);
break;
case 'R':
case 'r':
printf("For a rectangle with a width of %.2f and a height of %.2f,\n",
object.fig.rectangle.width, object.fig.rectangle.height);
printf("the area is %.2f and the perimeter is %.2f\n\n",
object.fig.rectangle.area, object.fig.rectangle.perimeter);
break;
case 'S':
case 's':
printf("For a square with a side length of %.2f, the area is %.2f and the perimeter is %.2f\n\n",
object.fig.square.side, object.fig.square.area, object.fig.square.perimeter);
break;
default:
printf("Error in shape code detected in print_figure\n\n");
}
}

========================================================================================

Shape.c figure t object; printf("Enter a letter to indicate the object shape or Q to quit.In) printf("C (circle), R (rectangle), or S (square): "; scanf(" %С",&object, shape); // update this line 67 68 70 71 72 73 74 75 CAUsers User DocumentslShape.exe rea and Perimeter Computation Program switch (object.shape) case C: case C Enter a letter to indicate the object shape or Q to quit. (circle), R (rectangle), Enter radius: 7 or s (square): C printf("Enter radius: "); scanf("%1f", &object . fig . circle.radiusFor a circle with a radius of 7.00, the area is 153.94 and the circumference is 43.98 break; 78 79 80 81 82 83 case 'R case 'r': Enter a letter to indicate the object shape or Q to quit. (circle), R (rectangle), or s (square): r Enter Height: 10 Enter width: 12 printf("Enter Height: ); scant("%1f", &object.fig. rectangle.he1E printf( Enter width: "); scanf("%1f", &object.fig.rectangle.widFor a rectangle with a width of 12.ee and a height of 18.00, break; the area is 129.00 and the perimeter is 44 .0θ 85 86 87 case 'S' case 's Enter a letter to indicate the object shape or Q to quit. (circle), R (rectangle), or s (square):s For a square with a side length of 12.00, the area is 144.00 and the perimeter is 48.00 Enter a letter to indicate the object shape or Q to quit. printf("Enter length of a side: " scant("%1f", &object.fig.square.side);Enter length of a side: 12 break; 90 default: //Error is treated as a QUIT 91 s th Compile Log Debug鳳Find Results Close (circle) R (rectangle), or S (square) q Compilation results... Process exited after 13.91 seconds with return value e Press any key to continue -Errors: 0 - Warnings: 0 - Output Filename: C:\Users\User\Documents\s - Output Size: 154.529296875 KiB -Compilation Time: 0.34s