In this program, the user is asked to enter any one of the operators +, -, *, / and also two operands. The operation chosen by the user is carried out on the two operands.
#include<stdio.h>
int main()
{
int a,b,res;
char c;
printf ("Enter any one operator +, -, *, / n");
scanf("%c", &c);
printf ("n Enter two numbers n");
scanf ("n %d n %d",&a, &b);
switch(c)
{
case '+': res=a+b;
printf("n The sum is %d",res);
break;
case '-': res=a-b;
printf("n The difference is %d",res);
break;
case '*': res=a*b;
printf("n The product is %d",res);
break;
case '/': res=a/b;
printf("n The quotient is %d",res);
break;
default: printf ("n Invalid entry");
}
return 0;
}
Here, the operator given by user is stored in variable c and the two operands are stored in variable a and b. The operator in variable c is checked against a list of labels in the switch statement. When a matching label is found, the list of operations associated with the label is executed meaning that if the variable c is equal to ‘+’ sign then the operations res=a+b and the statement “The sum is …“ is executed and the rest of the operations inside the switch statement is skipped. If the user enters other characters than +, -, *, / then “Invalid Entry” is displayed.
The program can also be written by using else if statement as:
#include<stdio.h>
int main()
{
int a, b, res;
char c;
printf ("Enter any one operator +, -, *, / n");
scanf("%c", &c);
printf ("n Enter two numbers n");
scanf ("n %d n %d",&a, &b);
if (c=='+')
{
res=a+b;
printf("n The sum is %d",res);
}
else if(c== '-')
{
res=a-b;
printf("n The difference is %d",res);
}
else if(c== '*')
{
res=a*b;
printf("n The product is %d",res);
}
else if(c==’/’)
{
res=a/b;
printf("n The quotient is %d",res);
}
else
{
printf ("n Invalid entry");
}
return 0;
}
Here, the character in variable c is check against the if condition and the else if conditions. When the condition that matches with the character in variable c is found, the statements associated with that variables is executed. If no matching condition is found then “Invalid Entry” is displayed.
Output:
Enter any one operator +, -, *, / + Enter two numbers 5 3 The sum is 8
Enter any one operator +, -, *, / / Enter two numbers 100 20 The quotient is 5