Why is this prgram not working in C? - c

Question

I program doesn't work after entering P or A. why?
it's challenge from udemy course. I am just a beginner in programming :)
#include <stdio.h>
#include <stdlib.h>
int main()
{
float height=0;
float width=0;
float area=0;
float perimeter=0;
printf("Enter height of rectangle :");
scanf("%f",&height);
printf("Enter width of rectangle :");
scanf("%f", &width);
char choice;
printf("Enter P for perimeter and A for area: ");
scanf(" %c", choice);
if(choice=='P' || choice=='p'){
printf("Width: %f", width);
printf("Height: %f", height);
perimeter= 2.0*(height*width);
printf("Perimeter of rectangle is: %f", perimeter);
}else if(choice=='A' || choice=='a'){
printf("Width: %f", width);
printf("Height: %f", height);
area= (height*width);
printf("Area of rectangle is: %f", area);
}else
printf("Invalid Input");
}

Answer 1

Correct this as follows:
scanf(" %c", &choice);
&choice will point to an address where you want to store the value.

Answer 2

This is not working Because you forgot & in scanf(" %c", choice); . It should be scanf(" %c", &choice); . In scanf function , you have to provide the address of the item to be scanned (Similar to scanf("%f", &height);).
Modified code :-
#include <stdio.h>
#include <stdlib.h>
int main()
{
float height = 0;
float width = 0;
float area = 0;
float perimeter = 0;
printf("Enter height of rectangle :");
scanf("%f", &height);
printf("Enter width of rectangle :");
scanf("%f", &width);
char choice;
printf("Enter P for perimeter and A for area: ");
scanf(" %c", &choice);
if (choice == 'P' || choice == 'p')
{
printf("Width: %f", width);
printf("Height: %f", height);
perimeter = 2.0 * (height * width);
printf("Perimeter of rectangle is: %f", perimeter);
}
else if (choice == 'A' || choice == 'a')
{
printf("Width: %f", width);
printf("Height: %f", height);
area = (height * width);
printf("Area of rectangle is: %f", area);
}
else
printf("Invalid Input");
}
Output :-
Enter height of rectangle :4
Enter width of rectangle :5
Enter P for perimeter and A for area: A
Width: 5.000000Height: 4.000000Area of rectangle is: 20.000000
I recommend to add \n before your printf() statements for better readability.