Why modular programming is needed in C - See It in Action

Why Modular Programming is Needed

📖 Scenario: Imagine you are building a simple calculator program in C. Instead of writing all the code in one big block, you want to organize it into smaller parts. This helps you understand, fix, and improve your program easily.

🎯 Goal: You will create a small C program that uses modular programming by dividing the calculator tasks into separate functions. This will show why modular programming is helpful.

📋 What You'll Learn

Create a function called add that takes two integers and returns their sum.

Create a function called subtract that takes two integers and returns their difference.

Create a function called multiply that takes two integers and returns their product.

Create a function called divide that takes two integers and returns their quotient as a float.

Use these functions in the main function to perform calculations and print the results.

💡 Why This Matters

🌍 Real World

Modular programming is used in real software projects to keep code organized and easy to maintain, especially when many people work together.

💼 Career

Understanding modular programming is essential for software developers to write clean, reusable, and scalable code.

1

Create the add function

Write a function called add that takes two integers named a and b and returns their sum as an integer.

C

#include 

// Your code here

int main() {
    return 0;
}

Need a hint?

Define a function with int add(int a, int b) and return a + b.

2

Create the subtract function

Write a function called subtract that takes two integers named a and b and returns their difference as an integer.

C

#include 

int add(int a, int b) {
    return a + b;
}

// Your code here

int main() {
    return 0;
}

Need a hint?

Define a function with int subtract(int a, int b) and return a - b.

3

Create the multiply and divide functions

Write two functions: multiply that takes two integers a and b and returns their product as an integer, and divide that takes two integers a and b and returns their quotient as a float.

C

#include 

int add(int a, int b) {
    return a + b;
}

int subtract(int a, int b) {
    return a - b;
}

// Your code here

int main() {
    return 0;
}

Need a hint?

Define multiply to return a * b and divide to return (float)a / b.

4

Use the functions in main and print results

In the main function, call add(10, 5), subtract(10, 5), multiply(10, 5), and divide(10, 5). Print each result on its own line with printf.

C

#include 

int add(int a, int b) {
    return a + b;
}

int subtract(int a, int b) {
    return a - b;
}

int multiply(int a, int b) {
    return a * b;
}

float divide(int a, int b) {
    return (float)a / b;
}

int main() {
    // Your code here
    return 0;
}

Need a hint?

Use printf to print each result with labels and newline characters.