Learn C++
from Zero to Expert

Structure of a C++ Program

Every C++ program has a basic structure that you need to understand. Let's analyze the main components:

• #include <iostream> - Includes the library for input/output
• int main() - The main function, the starting point of the program
• std::cout - The object for displaying text in the console
• return 0; - Indicates that the program ended successfully

#include <iostream>
using namespace std;

int main() {
    // Declare a variable
    string name = "C++";
    int year = 1983;
    
    // Display in console
    cout << "I'm learning " << name << endl;
    cout << "Created in " << year << endl;
    
    return 0;
}

Variables and Data Types

C++ is a statically typed language - you must declare the type of each variable:

• int - Integers (e.g.: 42, -17, 0)
• double - Decimal numbers (e.g.: 3.14, -0.5)
• char - A single character (e.g.: 'A', '7')
• string - String of characters (e.g.: "Hello!")
• bool - Logical values (true or false)

// Variable declarations
int age = 25;
double salary = 3500.50;
char letter = 'A';
string name = "John";
bool student = true;

// Constants
const double PI = 3.14159;
const int MAX_STUDENTS = 30;