Rob Miles

Oh, and one other thing. There is a convention that the name of the file which contains a particular class should match the class itself, in other words the program above should be held in a file called GlazerCalc.cs.

void

A void is nothing. In programming terms the void keyword means that the method we are about to describe does not return anything of interest to us.

Except for Main. This method (and there must be one, and only one such method) is where your program starts running.

Programmer’s Point: Know where your data comes from

In fact, given the limitations in the accuracy to which people can read tape measures, and the fact that we are not going to make any windows as wide as the universe, a double precision floating point number is overkill for this application. You would instead ask the customer if it is OK to just express the dimensions in millimetres instead.

All these decisions are driven by the metadata (data about data) that you gather when you are finding out about the system you are creating

The ; character is actually very important. It tells the compiler where a given statement ends. If the compiler does not find one of these where it expects to see one it will produce an error.