array syntax in C

Question

What is the difference between

int * a[10];

and

int (*b)[10];

I know that the first one is an array of pointers to integers, but what is the second one? If I try assigning

int (*c)[10] = a;

what am I actually doing to c?

Answer 1

See if you can install the cdecl command for your system. (On Ubuntu, sudo apt-get install cdecl.) There's also a web interface at cdecl.org.

Here's what it told me for your examples on my system:

$ cdecl
Type `help' or `?' for help
cdecl> explain int * a[10];
declare a as array 10 of pointer to int
cdecl> explain int (*b)[10];
declare b as pointer to array 10 of int
cdecl> 

Answer 2

Second one is a pointer to an array of 10 integers. Where? God knows; you never initialized it.

If you assign a to it, you're making it point to the same array of 10 integers that a pointed to... nothing fancy.