C++ Reference
Your complete guide to C++ programming language
🚀 What is C++?
C++ is a powerful, general-purpose programming language that supports object-oriented, procedural, and generic programming. It's widely used for system software, game development, and high-performance applications.
// Your first C++ program
#include <iostream>
using namespace std;
int main() {
cout << "Hello, C++!" << endl;
return 0;
}
Output:
Hello, C++!
Key C++ Features
Object-Oriented
Classes, objects, inheritance, polymorphism
class Car {
public:
void start() { cout << "Engine started!"; }
};High Performance
Fast execution and memory control
int* ptr = new int(42);
delete ptr; // Manual memory managementRich Library
Standard Template Library (STL)
#include <vector>
vector<int> numbers = {1, 2, 3, 4, 5};Cross-Platform
Runs on Windows, Linux, macOS
// Same code works everywhere
cout << "Platform independent!";🔹 Basic C++ Structure
Every C++ program is built upon a fundamental structure that includes necessary headers, a main function, and
a return statement. The #include <iostream> directive brings in standard
input/output functionalities. Execution begins at the int main() function, which serves as the
program's entry point. The body of main contains the executable statements, and it typically ends with
return 0;, signaling successful completion to the operating system. Understanding this skeleton is the
first step in writing any C++ application, from simple console utilities to complex system software.
// Include necessary headers
#include <iostream>
// Use standard namespace
using namespace std;
// Main function - program entry point
int main() {
// Your code here
cout << "Welcome to C++!" << endl;
// Return 0 for successful execution
return 0;
}Output:
Welcome to C++!
🔹 Variables and Data Types
Variables are named memory locations used to store and manipulate data, and their behavior is defined by
their associated data type. Declaring a variable (e.g., int age;) allocates memory and
specifies what kind of data it will hold. Initialization assigns an initial value at the point of declaration. The
choice of data type (like char for a grade or int for an age) dictates the operations that
can be performed and the memory used. Proper variable naming and type selection are cornerstones of writing clear,
efficient, and maintainable code.
#include <iostream>
using namespace std;
int main() {
// Integer
int age = 25;
// Floating point
double price = 19.99;
// Character
char grade = 'A';
// String
string name = "John";
// Boolean
bool isStudent = true;
cout << "Name: " << name << endl;
cout << "Age: " << age << endl;
cout << "Grade: " << grade << endl;
return 0;
}Output:
Name: John
Age: 25
Grade: A