C Program for Simple Calculator

In this tutorial, i am going to show you how to create simple calculator program in c programming language using switch case and if else statement.

All C Programs for Simple Calculator

• C Program for Simple Calculator using Switch Case
• C Program for Simple Calculator using If else

C Program for Simple Calculator using Switch Case

#include <stdio.h>
int main() {
  char op;
  double first, second;
  printf("Enter an operator (+, -, *, /): ");
  scanf("%c", &op);
  printf("Enter first numbers: ");
  scanf("%lf", &first);
  
  printf("Enter second numbers: ");
  scanf("%lf", &second);
  switch (op) {
    case '+':
      printf("%.1lf + %.1lf = %.1lf", first, second, first + second);
      break;
    case '-':
      printf("%.1lf - %.1lf = %.1lf", first, second, first - second);
      break;
    case '*':
      printf("%.1lf * %.1lf = %.1lf", first, second, first * second);
      break;
    case '/':
      printf("%.1lf / %.1lf = %.1lf", first, second, first / second);
      break;
    // operator doesn't match any case constant
    default:
      printf("Error! operator is not correct");
  }
  return 0;
}

The result of the above c program; as follows:

Enter an operator (+, -, *, /): +
Enter first numbers: 5
Enter second numbers: 2
5.0 + 2.0 = 7.0

C Program for Simple Calculator using If else

#include <stdio.h>
 
int main()
{
	char Operator;
	float num1, num2, result = 0;
	
	printf("\n Please Enter an Operator (+, -, *, /)  :  ");
  	scanf("%c", &Operator);
  	
	printf("\n Please Enter the Values for two Operands: num1 and num2  :  ");
  	scanf("%f%f", &num1, &num2);
  	
  	if(Operator == '+')
  	{
  		printf("\n The result of %.2f + %.2f  = %.2f", num1, num2, num1 + num2);
  	}
  	else if(Operator == '-')
  	{
  		printf("\n The result of %.2f - %.2f  = %.2f", num1, num2, num1 - num2);
  	}
  	else if(Operator == '*')
  	{
  		printf("\n The result of %.2f * %.2f  = %.2f", num1, num2, num1 * num2);
  	}
  	else if(Operator == '/')
  	{
  		printf("\n The result of %.2f / %.2f  = %.2f", num1, num2, num1 / num2);
  	}
  	else
  	{
  		printf("\n You have enetered an Invalid Operator ");
	}
	
  	return 0;
}

The result of the above c program; as follows:

Please Enter an Operator (+, -, *, /)  :  *
Please Enter the Values for two Operands: num1 and num2  :  5 2
The result of 5.00 * 2.00  = 10.00

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