Learn C++ from scratch

What is C++?

C++ is a high-level programming language that allows you to control many details of your program.

It’s widely used in high-performance applications, game development, and embedded systems. The possibilities are immense!

Setting up the environment

Before you start programming in C++, you will need to download and install a development environment.

How does C++ work?

Now you write your code in C++. To run it, you need to compile it. For example like this:

g++ program.cpp -o program

The compiler translates your code into a language that the computer understands—your first program!

Variables

Variables in C++ allow you to store data (like numbers, text, or boolean values).

int age = 25;
int total = age + 25;

C++ lets you perform mathematical operations. For example, adding, subtracting, multiplying, dividing—and much more!

Conditionals

With conditionals in C++, you can make the program make decisions. We use if, else if, and else to execute code only if a condition is true.

if (age > 18) {
  cout << "You are an adult";
}

Loops

Loops in C++ allow you to repeat actions. Use for, while, or do-while to repeat tasks several times until a condition is met.

for (int i = 0; i < 10; i++) {
  cout << i;
}

Functions

Functions are blocks of code that perform specific tasks.

int sum(int a, int b) {
  return a + b;
}

They allow you to organize and reuse your code easily.

Collections

Collections are structures that allow you to store multiple values. The simplest one is an array.

int numbers[5] = {1, 2, 3, 4, 5};
vector<int> vec = {1, 2, 3, 4, 5};

In C++, we also have vectors, which are more flexible because they can change size dynamically.

Classes and objects

C++ is an object-oriented language. This means you can create classes

class Person {
  public:
    string name;
    void greet() { cout << "Hello, " << name; }
};

These represent real-world objects, with properties and behaviors.

Pointers and references

In C++, pointers allow you to work directly with memory.

A pointer is a variable that stores the memory address of another variable. References are aliases for variables, and both concepts are essential in memory management.

int* ptr = &age;
cout << *ptr;  // Prints the value of 'age'

Use them with care!

Libraries

A library is a set of predefined functions and classes that you can use in your programs. You can include them in your project like this:

#include <vector>
using namespace std;