c++ - How does a pointer to a pointer correspond to a 2D array? -

i know question asked before, don't understand in context:

here's code i'm trying examine, i'll comment it. please let me know i'm wrong

int **a;                    // declaring pointer pointer  = new int*[n];            // assigning pointer newly-allocated                              // space (on heap) array                             // of [size n] of pointers integers  (i = 0; < n; ++i)     // looping 0 n-1     a[i] = new int[n];      // assigning each slot's pointer                              // new array of size n?  (i = 0; < n; ++i)     // loop through rows     (j = 0; j < n; ++j) // loop through each column current row         a[i][j] = 0;        // assign value 0 

please let me know i'm wrong. don't understand a = new int*[n]; i'm trying figure out using common sense i'm having troubles.

thank you!

your code , comments correct. clear confusion pointers:

• a 2d array array of arrays.
• in order allow arrays have dynamic size (i.e. size n not known @ compile time), array of pointers created. each pointer in array points array of ints.
• the resulting structure similar array of arrays - it's array of pointers arrays. pointers there because cannot have e.g. int a[n][n]; @ compile time because size not known.

here's diagram of this:

> [       ]      //">" pointer, pointing @ array ([ ])       [ ]  [ ]  [ ] > [  ^    ^    ^ ]  // array array of pointers "^", each of points array