Isn't double[][] equivalent to **double?

Question

I\'m asking this because my program have two functions to multiply matrices, they multiply only 4x4 and 4x1 matrices. The headers are:

 double** mult4x1(doub         


        

Answer 1

There is no type [][]. What you have is in fact m2 which is an array of arrays of size 4 of type double and m1 which is an array of arrays of size 1. An array of arrays of size 4 is not equivalent to double pointer.

Answer 2

Well I hope I will not turn out stupid here but the notation double [][] is also used when you are addressing a continuous block of memory, while double** is not necessarily continuous.

I think that is the reason behind the error. Even though you can use the same semantics to access values, they are actually different types.

Answer 3

No they definitely are not equivalent the former represents a 2D array of doubles while as latter represents a pointer to pointer to double.