C program uses switch..case to make a simple calculator

Comprehensive Collection of C Programming Examples

In this example, you will learn to create a simple calculator using the switch statement in C programming language.

To understand this example, you should understand the followingC programming languageTopic:

• C switch statement

• C break and continue statements

This program requires an arithmetic operator+, -, *, /and two operands. Then, it performs the calculation on the two operands based on the operator entered by the user.

A simple calculator using the switch statement

#include <stdio.h>
int main() {
　　　　char operator;
　　　　double first, second;
　　　　printf("Input operator (+,　-,　*,): ");
　　　　scanf("%c", &operator);
　　　　printf("Input two operands: ");
　　　　scanf("%lf %lf", &first, &second);
　　　　switch (operator) {
　　　　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;
　　　　　　　　//The operator does not match any case
　　　　default:
　　　　　　　　printf("Error! Operator is incorrect");
　　　　}
　　　　return 0;
}

Output result

Input operator(+,　-,　*,):　*
Input two operands:　1.5
4.5
1.5　*　4.5　=　6.8

user input*the operator is stored in operator. Moreover, two operands1.5and4.5stored separately in first and second.

Due to the operator*With case '*' : matches, so the program's control jumps to

printf("%.1lf　*　%.1lf = %.1lf", first, second, first　*　second);

This statement calculates the result and displays it on the screen.

Finally, the break; statement ends the switch statement.

Comprehensive Collection of C Programming Examples