What type, name of a multidimensional array is?

Question

I am trying to grasp the concept of pointers in multidiensional arrays and there are some things I would like to clarify. Let's have a small 2-D array B for an example:

int B[4][3];
int i;        //ranges from 0-3

My question is what types are the following elements:

B+i      
*(B+i)

What confuses me is that when I run:

std::cout<<B;
std::cout<<*B;

The outputs are the same. I would be glad if someone could clarify that.

Answer 1

B decays to int (*)[3] . The rule here is that the leftmost extent is removed, and a * is added instead.

Thus, B+i is int (*)[3] too.

And thus, *(B+i) is int [3] (which decays to int * ).

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The fact that B == *B is not hard to explain. B is an address of the first subarray (aka address of B[0] ) and *B is an address of the first element of that subarray (aka address of B[0][0] ).

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Explanation on types:

All multidimensional arrays in C/C++ are in fact nested 1D arrays.

Your int B[4][3]; can be considered a TB[4] , where T is int [3] .

Then the decay happens as for normal 1D array: TB[4] becomes T (*) . Because T is int [3] , T (*) is int (*)[3] .