1D array decays to pointer, but 2D array doesn't do so, why? [duplicate]

Answer 1

A two-dimensional array is an array of arrays.

An "array of T" is - in most contexts - converted to a "pointer to T, so an "array of T[N]" is converted to a "pointer to T[N]".

Since the memory representation of an

int arr[M][N];

is completely different from

int **dptr = malloc(M*sizeof *dptr);
for(int i = 0; i < M; ++i) {
    dptr[i] = malloc(N*sizeof *dptr[i]);

an int[M][N] cannot even be converted to an int**.