Specifying initialization

Specifying initialization

What happens if you want to give a variable an initial value? One direct way to do this is simply to assign the value at the point you define the variable in the class. (Notice you cannot do this in C++, although C++ novices always try.) Here the field definitions in class Measurement are changed to provide initial values:

This method can have arguments, of course, but those arguments cannot be other class members that haven't been initialized yet. Thus, you can do this:

But you cannot do this:

This is one place in which the compiler, appropriately, does complain about forward referencing, since this has to do with the order of initialization and not the way the program is compiled.

This approach to initialization is simple and straightforward. It has the limitation that every object of type Measurement will get these same initialization values. Sometimes this is exactly what you need, but at other times you need more flexibility.