Shriramana Sharma wrote:
> > That's called the initializer list. I suggest you get a book that
> > explains these things. C++ Primer or The C++ Programming Language
> > would be good.
>
> Thanks. I am reading/referring to a PDF copy of Thinking in C++ but of course
> without knowing the name of this syntax "initializer list" I cannot search
> through the PDF.
>
> Now what I would like to know is: Is
>
> > > CAA2DCoordinate(): X(0), Y(0) {};
>
> much different from:
>
> > > CAA2DCoordinate() { X = 0; Y = 0; }
>
> ? Seeing as X and Y are not const-s, I do not see the point in initializing
> outside the (empty) braces. If they were const-s, TICP tells me that they
> must be initialized before the *start* of the function so the X(0) syntax is
> necessary. But here they are not const-s...
In which case, both forms are valid, and equivalent.
You also need to use an initialiser if you need to initialise the
member variable through a constructor.
Given that you have to use an initialiser in some cases, and you are
allowed to use it in the other cases (i.e. non-const primitive types),
you may as well *always* use initialisers to initialise member
variables, rather than a mix of initialisers and assignments.
--
Glynn Clements <glynn@xxxxxxxxxxxxxxxxxx>
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