C++ Introduction

C++ is a programming language used to write programs. A program is a set of instructions that a computer follows.

A first program

This program has the basic shape of every program in this course. It prints one line of text.

#include <iostream>

int main() {
  std::cout << "My first C++ program\n";
  return 0;
}

Two prints in order

Two print lines run in order. The first line prints before the second line.

#include <iostream>

int main() {
  std::cout << "First line\n";
  std::cout << "Second line\n";
  return 0;
}

Example

#include <iostream>

int main() {
  std::cout << "C++ is a programming language\n";
  std::cout << "C++ programs run on many computers\n";
  std::cout << "C++ code is written as plain text\n";
  return 0;
}

Key points

C++ code is written as plain text in a file.
A compiler is a tool that turns code into a form a computer can run.
The #include <iostream> line brings in tools for printing text.
int main() is the starting point of the program.
std::cout prints text to the screen.

In this example, three print lines run in order. The first line says C++ is a programming language. The second line says C++ programs run on many computers. The third line says C++ code is written as plain text.

Note

File names for C++ code often end in .cpp.

Try it Yourself

Edit the code, then press Run.

Running is simulated · Programiz C++ Compiler

#include <iostream>

int main() {
  std::cout << "C++ is a programming language\n";
  std::cout << "C++ programs run on many computers\n";
  std::cout << "C++ code is written as plain text\n";
  return 0;
}

Exercise

Which line prints text to the screen?

std::cout << "Hello\n"; #include <iostream> int main() { return 0;