Lines beginning with a hash sign (#) are directives for the preprocessor. They are not regular code lines
with expressions but indications for the compiler's preprocessor. In this case the directive #include
<iostream> tells the preprocessor to include the iostream standard file. This specific file (iostream)
includes the declarations of the basic standard input-output library in C++, and it is included because its
functionality is going to be used later in the program.
with expressions but indications for the compiler's preprocessor. In this case the directive #include
<iostream> tells the preprocessor to include the iostream standard file. This specific file (iostream)
includes the declarations of the basic standard input-output library in C++, and it is included because its
functionality is going to be used later in the program.