1. a small C++ program
#include <iostream>
int main()
{
std::cout<<"Hello, World."<<std::endl;
return 0;
}
(1) The // Characters begin a comment, which extends to the end of the line.
(2) On #include, many c++ facilities are part of standard library rather than being part of core language.
(3) The main function is required to yield a integer as a result. A zero value indicates success, any other value means there was a problem.
2. Some concepts
comment, core language, standard library, #include directives, angle brackets, standard headers, function, statements, curly brackets, output operator, standard output stream, expression, result, side effect, type, left-associative, manipulator, scope, namespace, scope operator, qualified name, free form, string literals, definitions, main function, semicolons, expression statement, null statement.