C Program to make Calculator using switch case

By  ShC    5 - 05 January, 23
C program to make calculator using switch case

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Here is an article on how to create a simple calculator program using a switch case statement in C:


Creating a Calculator Program in C using a Switch case Statement

Calculator programs are a common project for beginners to learn a programming language. In this article, we will create a simple calculator program in C using a switch case statement.

To begin, we will first need to include the stdio.h header file, which provides functions for input and output in C.

 C program to make calculator using switch case

#include

Next, we will define the main function where the program will start execution. Inside the main function, we will declare variables for the operator and operands. We will use a char type for the operator and double types for the operands.

int main() { char operator; double firstNumber, secondNumber;

Next, we will prompt the user to enter an operator by using the printf function and then use the scanf function to read the operator entered by the user.

printf("Enter an operator (+, -, *, /): ");
scanf("%c", &operator);

Then, we will prompt the user to enter two operands and read them using the scanf function.

printf("Enter two operands: ");
scanf("%lf %lf", &firstNumber, &secondNumber);

Now, we will use a switch statement to perform the corresponding operation based on the operator entered by the user. The switch statement will have cases for each of the four possible operators: +-*, and /. For each case, we will use the printf function to print the result of the operation.

switch(operator) {
case '+':
printf("%.1lf + %.1lf = %.1lf", firstNumber, secondNumber, firstNumber + secondNumber);
break;
case '-':
printf("%.1lf - %.1lf = %.1lf", firstNumber, secondNumber, firstNumber - secondNumber);
break;
case '*':
printf("%.1lf * %.1lf = %.1lf", firstNumber, secondNumber, firstNumber * secondNumber);
break;
case '/':
printf("%.1lf / %.1lf = %.1lf", firstNumber, secondNumber, firstNumber / secondNumber);
break;

Finally, we will include a default case for when the operator entered by the user does not match any of the cases. This will handle any invalid input by the user.

// operator doesn't match any case default: printf("Error! operator is not correct"); }

To finish the program, we will return 0 from the main function to indicate that the program has successfully completed.

return 0; }

Here is an example of a simple calculator program using a switch case statement in C:

#include
int main() {
char operator;
double firstNumber, secondNumber;
printf("Enter an operator (+, -, *, /): ");
scanf("%c", &operator);
printf("Enter two operands: ");
scanf("%lf %lf", &firstNumber, &secondNumber);
switch(operator) {
case '+':
printf("%.1lf + %.1lf = %.1lf", firstNumber, secondNumber, firstNumber + secondNumber);
break;
case '-':
printf("%.1lf - %.1lf = %.1lf", firstNumber, secondNumber, firstNumber - secondNumber);
break;
case '*':
printf("%.1lf * %.1lf = %.1lf", firstNumber, secondNumber, firstNumber * secondNumber);
break;
case '/':
printf("%.1lf / %.1lf = %.1lf", firstNumber, secondNumber, firstNumber / secondNumber);
break;
//operator doesnt match any case
default:
printf("Error! operator is not correct");
}
return 0;
}
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