Defining Arrays

Defining Arrays

[Nuwan Kodagoda]

Hi,

	I am very confused about the way arrays are initialized under g++.  (I am 
using Red Hat Linux 9)

	int size;
	cin >> size;
	int myarray[size];

	According to what I had known earlier this should not be possible since 
the size of the array should be a constant.

	But this seems to work perfectly under g++.  To my knowledge in Standard 
C++ you are not allowed to use a variable during a array declaration.

	If you can create dynamic arrays this way, why bother using dynamic arrays 
using pointers ?

	e.g.

	int size;
	cin >> size;
	int * pmyarray = new int[size];


Nuwan

Re: Defining Arrays

[Wayne]

If you take a minute to check out the GCC documentation, or google
on it, wou will find that this is a fallout of a partial 
implementation of some C99? functionality.  One important note
to keep in mind about the two different ways you dynamically
created arrays.  The first creates an array on the stack, which
is very limited space, the second creates it on the usually
much larger heap.  They are not equivalent means of doing the
same thing.

Wayne