Performing Arithmetic Operations using Switch-Case

Here is a program that performs arithmetic operations using switch case in C programming language. The use of switch case provides more control to the user by asking the user which operation he/she wants to perform.

#include<stdio.h>
#include<conio.h> 
void main() 
{ 
 int n1, n2, ch ; 
 clrscr() ; 
 printf("Enter the first number : ") ; 
 scanf("%d", &n1) ; 
 printf("\nEnter the second number : ") ; 
 scanf("%d", &n2) ; 
 printf("\n[1] -> Addition ") ; 
 printf("\n[2] -> Subtraction ") ; 
 printf("\n[3] -> Multiplication ") ; 
 printf("\n[4] -> Division ") ; 
 printf("\n\nEnter your choice <1...4> : ") ; 
 scanf("%d", &ch) ; 
 switch(ch) 
 { 
  case 1 : 
   printf("\n%d + %d = %d", n1, n2, n1 + n2) ; 
   break ; 
  case 2 : 
   printf("\n%d - %d = %d", n1, n2, n1 - n2) ; 
   break ; 
  case 3 : 
   printf("\n%d * %d = %d", n1, n2, n1 * n2); 
   break ; 
  case 4 : 
   printf("\n%d / %d = %.2f", n1, n2, (float)n1 / n2); 
   break ; 
  default : 
   printf("\nInvalid choice"); 
   break ; 
 } 
 getch(); 
}

Output of above program

Enter the first number : 15

Enter the second number : 3

[1] -> Addition
[2] -> Subtraction
[3] -> Multiplication
[4] -> Division

Enter your choice <1...4> : 4

15 / 3 = 5.00

Explanation of above program

The program first asks user to enter two numbers, then it shows four options to the user. When user enters a choice the program take that value and passes it to the switch-case statement. Here the program picks a case based on the value that user entered before and executes that particular case. If no case matches the users request, default case will be executed.

If you notice you'll see that inside each case there is a break statement. Now what is the need  to use break statement inside each case? Read it here - Why use break statement inside switch case.