Recap: Modular Calculator

Part of the Object Oriented Programming section of Coddy's C journey — lesson 5 of 61.

Challenge

Easy

Let's build a modular calculator that performs basic arithmetic operations, organized across three files to practice everything you've learned about modular programming in C.

You'll create three files:

calc.h: Your header file declaring three calculator functions: add, subtract, and multiply. Each function takes two integers and returns an integer. Protect your header with include guards using the symbol CALC_H.
calc.c: Your source file containing the implementations of all three operations. Remember to include your own header to ensure declarations and definitions stay in sync.
main.c: Your main file that includes the header and uses the calculator functions to perform operations based on input.

You will receive three integer inputs: a, b, and c.

In your main function, perform the following calculations and print each result on a separate line:

The sum of a and b
The result of subtracting c from a
The product of b and c

Print the results in this format:

Sum: {result}
Difference: {result}
Product: {result}

For example, with inputs 10, 5, and 3, the output would be:

Sum: 15
Difference: 7
Product: 15

Try it yourself

#include <stdio.h>
#include "calc.h"

int main() {
    int a, b, c;
    scanf("%d", &a);
    scanf("%d", &b);
    scanf("%d", &c);
    
    // TODO: Calculate the sum of a and b using the add function
    
    // TODO: Calculate the difference of a minus c using the subtract function
    
    // TODO: Calculate the product of b and c using the multiply function
    
    // TODO: Print the results in the required format:
    // Sum: {result}
    // Difference: {result}
    // Product: {result}
    
    return 0;
}