Computer Concept & Programming In C - Unit III - 6

Q.8 Simulate calculator using switch statement.               (AKTU. 2009-10)
Ans.
#include<stdio.h>
#include<conio.h>

void main()
{
  int flag = 0;
  float a, b, c;
  char choice;
  while(flag == 0)
  {
   clrscr();
   printf("\nCalculator");
   printf("\nPress 1 for ADDITION");
   printf("\nPress 2 for SUBSTRACTION");
   printf("\nPress 3 for MULTIPLICATION");
   printf("\nPress 4 for DIVISION");
   printf("\nPress any other key to exit.");
   choice = getche();
   switch(choice)
   {
    case '1' :
     printf("\nADDITION");
     printf("\n Enter the value of a\n");
     scanf("%f",&a);
     printf("\n Enter the value of b\n");
     scanf("%f",&b);
     c = a + b;
     printf("\n SUM = %f", c);
     getch();
     break;

   case '2'  :
     printf("\nSUBSTRACTION");
     printf("\n Enter the value of a\n");
     scanf("%f",&a);
     printf("\n Enter the value of b\n");
     scanf("%f",&b);
     c = a - b;
     printf("\n DIFFERENCE a - b = %f", c);
     getch();
     break;

   case '3'  :
     printf("\nMULTIPLICATION");
     printf("\n Enter the value of a\n");
     scanf("%f",&a);
     printf("\n Enter the value of b\n");
     scanf("%f",&b);
     c = a * b;
     printf("\n PRODUCT = %f", c);
     getch();
     break;

   case  '4' :
     printf("\nDIVISON");
     printf("\n Enter the value of a\n");
     scanf("%f",&a);
     printf("\n Enter the value of b\n");
     scanf("%f",&b);

     if((b == 0)&&( a < 0))
printf("\n - infinity");
     else if((b == 0)&&( a > 0))
    printf("\n + infinity");
  else
     {
c = a / b;
printf("\n QUOTIENT = %f", c);
     }
     getch();
     break;

   default :
    flag = 1;
    break;
   }/* end switch case*/
 }/*end while*/

}