Syntax and I/O

#include <iostream>
#include <string>

int main() {
    std::string name = "Ada";
    int age = 28;
    std::cout << name << " is " << age << " years old\n";
    return 0;
}

std::string is a real, safe string type -- unlike raw C strings, it manages its own memory and knows its own length. You can concatenate with +, compare with ==, and index with [] without ever touching a null terminator by hand:

std::string first = "Course: ";
std::string title = "C++ Mastery";
std::string full = first + title;      // concatenation
bool matches = (title == "C++ Mastery"); // true
char firstChar = title[0];               // 'C'
size_t len = title.length();             // 11

C++ has several ways to read input, and choosing the right one avoids a classic beginner trap. std::cin >> someInt reads a single whitespace-delimited token; std::getline(std::cin, someString) reads an entire line including spaces:

int age;
std::cin >> age;           // reads up to the next whitespace

std::cin.ignore();            // consume the leftover newline
std::string fullName;
std::getline(std::cin, fullName); // now reads the rest of the line correctly

Forgetting that leftover newline after a std::cin >> x is one of the most common C++ input bugs -- the next std::getline call appears to silently do nothing because it immediately reads the empty leftover line.

Formatting output precisely often requires <iomanip>. By default, std::cout prints doubles with up to 6 significant digits and trims trailing zeros, which is rarely what you want for currency:

#include <iomanip>

double price = 29.9;
std::cout << std::fixed << std::setprecision(2) << price; // 29.90

std::fixed switches to fixed-point notation and std::setprecision(2) fixes exactly two digits after the decimal point -- together they're the standard idiom for printing money-like values consistently.