Function calling in C++ - Mini Project: Build & Apply

Function calling

📖 Scenario: Imagine you are creating a simple calculator program that can add two numbers. You will write a function to add numbers and then call it to get the result.

🎯 Goal: Build a program that defines a function to add two integers and calls this function to display the sum.

📋 What You'll Learn

Define a function named add that takes two int parameters and returns their sum.

Create two integer variables with exact values 5 and 7.

Call the add function with these two variables.

Print the result of the function call.

💡 Why This Matters

🌍 Real World

Functions help organize code into reusable blocks, like a calculator that can add many pairs of numbers without rewriting code.

💼 Career

Understanding function calling is essential for writing clean, modular code in any software development job.

1

Create two integer variables

Create two integer variables called num1 and num2 with values 5 and 7 respectively.

C++

// Your code here

Need a hint?

Use int to declare variables and assign the exact values.

2

Define the add function

Define a function named add that takes two int parameters named a and b and returns their sum as an int.

C++

int num1 = 5;
int num2 = 7;

// Your code here

Need a hint?

Write the function header with two parameters and return their sum inside the function body.

3

Call the add function and store result

Call the add function with num1 and num2 as arguments and store the result in an integer variable called sum.

C++

int num1 = 5;
int num2 = 7;

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

// Your code here

Need a hint?

Use the function name add with the two variables inside parentheses and assign the result to sum.

4

Print the sum

Print the value of the variable sum using std::cout.

C++

int num1 = 5;
int num2 = 7;

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

int sum = add(num1, num2);

// Your code here

Need a hint?

Use std::cout << sum << std::endl; inside main() to print the sum.