array_name[], what does it mean?

microsoft/linux · 01-26-2006, 08:52 AM

When I was looking at the gtkpod/glibpod source code, I noticed a bunch of arrays without a set size. It looked something like

Code:

*array_name[]

I understand that the '*' means its a pointer, that is, it points ot a place in the memory. Why does it not specify the size of the array? I thought arrays were supposed to be used with

Code:

array_name[x]

Is it because it's pointer, that there is no need to set the size?

geeman2.0 · 01-26-2006, 09:06 AM

When you do something like

int array[5];

The [5] tells the compiler to reserve 5 integer sized units of memory.
Since in your example it's a pointer, it's not reserving any memory for the array, it only stores a memory address, so there's no reason to specify an array size, it will just end up pointing to some other existing array in memory.

You can still use the pointer with an array index once it's pointing to an array in memory.

dmail · 01-26-2006, 09:10 AM

these are both the same:
*array_name[] = **array_name;

you may have seen it before and not noticed,
int main(int argc, char* argv[])...
int main(int argc, char** argv)...