why "delete [][]... multidimensionalarray;" user c++ does exist

i always wondering there user deletion multi dimensional arrays customary c++ language.

if have combined pointer unparalleled dimensional array

int *array = new int[size];

the mislay looks like:

delete [] array;

that's great. nonetheless have twin dimension array, do

delete [][] twodimenstionalarray;

instead, should loop mislay items, example.

can anybody explain why?