C++ Tutorial Examples

Hello World

Create a hello_world.cpp file.

#include <iostream>

int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

This is a simple “Hello World” program.
It includes the iostream header, which provides functionality for input and output.
The main function is the entry point of the program, and it prints “Hello, World!” to the console using std::cout and then returns 0 to indicate successful execution.

Variables and Input/Output

Create a in_out.cpp file.

#include <iostream>

int main() {
    int number;
    std::cout << "Enter a number: ";
    std::cin >> number;
    std::cout << "You entered: " << number << std::endl;
    return 0;
}

This program demonstrates variable declaration (int number;), input from the user (std::cin >> number;), and output to the console (std::cout).
It prompts the user to enter a number, reads it, and then prints the entered number.

Arithmetic Operations

Create a calc.cpp file.

#include <iostream>

int main() {
    int a = 5, b = 3;
    std::cout << "Sum: " << a + b << std::endl;
    std::cout << "Difference: " << a - b << std::endl;
    std::cout << "Product: " << a * b << std::endl;
    std::cout << "Quotient: " << a / b << std::endl;
    return 0;
}

This program performs basic arithmetic operations (addition, subtraction, multiplication, and division) on two integers (a and b) and prints the results.

Conditional Statements

Create a cond.cpp file.

#include <iostream>

int main() {
    int number;
    std::cout << "Enter a number: ";
    std::cin >> number;

    if (number > 0) {
        std::cout << "Number is positive." << std::endl;
    } else if (number < 0) {
        std::cout << "Number is negative." << std::endl;
    } else {
        std::cout << "Number is zero." << std::endl;
    }

    return 0;
}

This program uses conditional statements (if, else if, else) to determine whether a number is positive, negative, or zero based on user input.

Loops

Create a loop.cpp file.

#include <iostream>

int main() {
    for (int i = 1; i <= 5; ++i) {
        std::cout << "Iteration " << i << std::endl;
    }

    int count = 0;
    while (count < 3) {
        std::cout << "While loop iteration " << count + 1 << std::endl;
        ++count;
    }

    return 0;
}

This program demonstrates the use of loops.
It has a for loop that iterates five times and a while loop that iterates three times.

Functions

Create a func.cpp file.

#include <iostream>

// Function declaration
int add(int a, int b);

int main() {
    int result = add(3, 4);
    std::cout << "Sum: " << result << std::endl;
    return 0;
}

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

This program defines a simple function add that takes two integers as parameters and returns their sum.
The function is declared before main and defined afterward.

Arrays

Create a arr.cpp file.

#include <iostream>

int main() {
    int numbers[] = {1, 2, 3, 4, 5};

    std::cout << "Array elements: ";
    for (int i = 0; i < 5; ++i) {
        std::cout << numbers[i] << " ";
    }
    std::cout << std::endl;

    return 0;
}

This program uses an array (int numbers[]) to store five integers and prints them using a for loop.

Strings

Create a str.cpp file.

#include <iostream>
#include <string>

int main() {
    std::string greeting = "Hello, ";
    std::string name = "Alice";

    std::cout << greeting + name << std::endl;

    return 0;
}

This program uses the std::string class to concatenate two strings and prints the result.

Pointers

Create a ptr.cpp file.

#include <iostream>

int main() {
    int number = 42;
    int* pointer = &number;

    std::cout << "Value: " << *pointer << std::endl;

    return 0;
}

This program demonstrates the use of pointers.
It declares an integer, creates a pointer to that integer, and prints the value pointed to by the pointer.

Classes and Objects

Create a obj.cpp file.

#include <iostream>
#include <string>

// Class definition
class Student {
public:
    std::string name;
    int age;

    void displayInfo() {
        std::cout << "Name: " << name << ", Age: " << age << std::endl;
    }
};

int main() {
    // Object creation
    Student student1;
    student1.name = "Bob";
    student1.age = 20;

    // Accessing class members
    student1.displayInfo();

    return 0;
}

This program defines a simple class Student with attributes name and age, and a member function displayInfo that prints the student’s information.
It then creates an object of the class and accesses its members.