Why input and output are required in C++ - See It in Action

Why input and output are required

📖 Scenario: Imagine you want to create a simple program that asks a user for their age and then tells them how old they will be next year. To do this, the program needs to get information from the user (input) and then show the result back to the user (output).

🎯 Goal: Build a small C++ program that takes a user's age as input and outputs their age next year.

📋 What You'll Learn

Use int variable to store age

Use std::cin to get input from the user

Use std::cout to display output to the user

Add 1 to the input age to calculate next year's age

💡 Why This Matters

🌍 Real World

Programs often need to ask users for information and then show results or messages based on that information.

💼 Career

Understanding input and output is essential for writing any interactive software, from simple tools to complex applications.

1

Create an integer variable called age

Write a line of code to declare an integer variable named age.

C++

#include 

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

Need a hint?

Use int age; to create the variable.

2

Get the user's age using std::cin

Write a line of code to read an integer from the user into the variable age using std::cin.

C++

#include 

int main() {
    int age;
    std::cin >> age;  // Your code here
    return 0;
}

Need a hint?

Use std::cin >> age; to get input from the user.

3

Calculate next year's age and store in next_age

Create an integer variable called next_age and set it to age + 1.

C++

#include 

int main() {
    int age;
    std::cin >> age;
    int next_age = age + 1;  // Your code here
    return 0;
}

Need a hint?

Use int next_age = age + 1; to calculate next year's age.

4

Print the result using std::cout

Write a line of code to print the text Your age next year will be: followed by the value of next_age using std::cout.

C++

#include 

int main() {
    int age;
    std::cin >> age;
    int next_age = age + 1;
    std::cout << "Your age next year will be: " << next_age << std::endl;  // Your code here
    return 0;
}

Need a hint?

Use std::cout << "Your age next year will be: " << next_age << std::endl; to print the message.

Try entering 30 as input to test.