Source: Code Academy

The Main Function

#include <iostream>

int main() 
{
  
  std::cout << "Expecto Patronum\\n";
  
}

In the code example above:

• Libraries to include in the program are initialized by the line: #include <selected library>
• Main function is initialized by the line: int main ()
• The main function code is between curly brackets {}: std::cout << "Expecto Patronum\n";
  • std::cout outputs to the terminal.
  • << is an operator.
  • Always enclose text in double quote brackets "".
  • \n is a command for a new line. Note that the slash is a backslash.
  • ; ends the statement.
  • cout:: is for output.

Compiling Via The Terminal

If you want to compile the program above, in the terminal use the command g++ and the name of the cpp file. The default filename output will be ./a.out.

g++ ExpectoPatronum.cpp

If you want to specify a file name output for compiling add -o FileName, like below.

g++ ExpectroPatronum.cpp -o ExpectoPatronum

Executing the Compiled Program

If you want to execute the file, use the command ./filename. The default filename is ./a.out.

./a.out

./ExpectoPatronum

Commenting

Comments are code that the machine will ignore while executing the code. Comments are purely for human readers to mark-up the code so that they or another person can understand the code more easily at a later time.