Question

NEED CODE

HELPS WITH C PROGRAMMING. ISSUES EXPLAINED IN BOLD.

COMPARING TWO LETTERS AND CALLING A FUNCTION.  

Problem are explained in bold
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define pi 3.1415

void Area (double n);
void VolSphere (double n);
void Circumference (double n);
void AllCalc (); // i dont know if the declaration of the function is correct AllCalc = AllCalculations

//function main begins program execution
int main (void)
{
puts("-Calculating Circle Circumference, Circle Area or Sphere Volume-\n");
void (*f[4]) (double) = {Circumference, Area, VolSphere, AllCalc};

int pick;
float r, r2;
char choice;

//suppose user want to enter radius = 10;

printf("\nWhat is the radius of the circle?: "); //the user can either enter: r 10 or R 10 (for the radius) or d 10 D10 (for the diameter)
scanf("%s%f", choice, &r2); //i am scanning letter and number to compare with d D r and R

if (choice == 'd' || 'D') // right here i am comparing choice with d or D. If user entered d 10 then i want to devide radius by 2. If not, remains the same
r = r2/2; //for some reason the program is not running i tried "strcmp(choice, "d")" but it didnt work either. I dont know if it is if statement or i am going the wrong way

else {
r = r2;

}

printf( "\nPick a number according to what you want to calculate:\n"
"0 = Circumference | 1 = Area | 2 = Volume | 3 = All Calc | 4 = End Program: ");
scanf( "%d", &pick);

while ( pick >= 0 && pick < 4 ) {
(*f[pick])(r);

printf( "\nPick a number according to what you want to calculate\n"
"0 = Circumference | 1 = Area | 2 = Volume | 3 = All calculations | 4 = End program: ");
scanf ( "%d", &pick);
}
}

void Circumference (double n)
{
puts("\n\n-CIRCUMFERENCE-");
printf( "\nThe radius is %.2f\n" , n);
printf( "The circumference of the circle is: %.2f\n" , 2 * pi * n);
}

void Area (double n)
{
puts("\n\n-AREA-");
printf( "\nThe radius is %.2f\n" , n);
printf( "The area of the circle is: %.2f\n" , pi * n * n);

}

void VolSphere (double n)
{

puts("\n\n-VOLUME-");
printf( "\nThe radius is %.2f\n" , n);
printf( "The volume of the circle is: %.2f\n" ,(4 * pi * n * n * n)/3);
}

void AllCalc () //Inside of this function i need to call all 3 (Volume, area, circumference) to make a summary of the calculations. Preferably using pointers

{

//here the output should be something like

Circumference is: ....

Volume is:......

Area is:........

}

Answer 1

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//gcc 5.4.0
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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define pi 3.1415

void Area (double n);
void VolSphere (double n);
void Circumference (double n);
void AllCalc (double n); // i dont know if the declaration of the function is correct AllCalc = AllCalculations

//function main begins program execution
int main (void)
{
puts("-Calculating Circle Circumference, Circle Area or Sphere Volume-\n");
void (*f[4]) (double) = {Circumference, Area, VolSphere, AllCalc};

int pick;
double r, r2;
char choice;

//suppose user want to enter radius = 10;

printf("\nWhat is the radius of the circle?: "); //the user can either enter: r 10 or R 10 (for the radius) or d 10 D10 (for the diameter)
scanf("%c %lf", &choice, &r2); //i am scanning letter and number to compare with d D r and R

if ((choice == 'd') || (choice == 'D')) // right here i am comparing choice with d or D. If user entered d 10 then i want to devide radius by 2. If not, remains the same
r = r2/2; //for some reason the program is not running i tried "strcmp(choice, "d")" but it didnt work either. I dont know if it is if statement or i am going the wrong way

else {
r = r2;

}

printf( "\nPick a number according to what you want to calculate:\n"
"0 = Circumference | 1 = Area | 2 = Volume | 3 = All Calc | 4 = End Program: ");
scanf( "%d", &pick);

while ( pick >= 0 && pick < 4 ) {
(*f[pick])(r);

printf( "\nPick a number according to what you want to calculate\n"
"0 = Circumference | 1 = Area | 2 = Volume | 3 = All calculations | 4 = End program: ");
scanf ( "%d", &pick);
}
}

void Circumference (double n)
{
puts("\n\n-CIRCUMFERENCE-");
printf( "\nThe radius is %.2f\n" , n);
printf( "The circumference of the circle is: %.2f\n" , 2 * pi * n);
}

void Area (double n)
{
puts("\n\n-AREA-");
printf( "\nThe radius is %.2f\n" , n);
printf( "The area of the circle is: %.2f\n" , pi * n * n);

}

void VolSphere (double n)
{

puts("\n\n-VOLUME-");
printf( "\nThe radius is %.2f\n" , n);
printf( "The volume of the circle is: %.2f\n" ,(4 * pi * n * n * n)/3);
}

void AllCalc (double n) //Inside of this function i need to call all 3 (Volume, area, circumference) to make a summary of the calculations. Preferably using pointers
{
void (*f[]) (double) = {Circumference, Area, VolSphere};
for(int i=0;i<3;i++)
(*f[i])(n);

}

**************************************************

Since AllCalc() function calls the volume, area, circumference functions to make summary of calculations, it can't print the value as those functions are returning void(nothing) and they are displaying the result in their function body itself.

Output:

---------

-Calculating Circle Circumference, Circle Area or Sphere Volume-                                                             

                                                                                                                             

                                                                                                                             

What is the radius of the circle?: d 20                                                                                      

                                                                                                                             

Pick a number according to what you want to calculate:                                                                       

0 = Circumference | 1 = Area | 2 = Volume | 3 = All Calc | 4 = End Program: 2                                                

                                                                                                                             

                                                                                                                             

-VOLUME-                                                                                                                     

                                                                                                                             

The radius is 10.00                                                                                                          

The volume of the circle is: 4188.67                                                                                         

                                                                                                                             

Pick a number according to what you want to calculate                                                                        

0 = Circumference | 1 = Area | 2 = Volume | 3 = All calculations | 4 = End program: 3

-CIRCUMFERENCE-                                                                                                              

                                                                                                                             

The radius is 10.00                                                                                                          

The circumference of the circle is: 62.83                                                                                    

                                                                                                                             

                                                                                                                             

-AREA-                                                                                                                       

                                                                                                                             

The radius is 10.00                                                                                                          

The area of the circle is: 314.15                                                                                            

                                                                                                                             

                                                                                                                             

-VOLUME-                                                                                                                     

                                                                                                                             

The radius is 10.00                                                                                                          

The volume of the circle is: 4188.67                                                                                         

                                                                                                                             

Pick a number according to what you want to calculate

0 = Circumference | 1 = Area | 2 = Volume | 3 = All calculations | 4 = End program: 4