printing values from 2d array using range for, subscripts and pointers

p_arr.cpp

#include <iostream>

int main()
{
    int ia[3][4] = {
        {0, 1 ,2 ,3},
        {4, 5, 6, 7},
        {8, 9, 10, 11}
    };

    /// using range for

    for (int (&i)[4] : ia) {
        for(int &i2 : i) {
            std::cout << i2 << " ";
        }
        std::cout << std::endl;
    }

    /// using subscript

    for (size_t i = 0; i != 3; ++i) {
        for (size_t i2 = 0; i2 != 4; ++i2) {
            std::cout << ia[i][i2] << " ";
        }
        std::cout << std::endl;
    }

    /// using pointers

    for (int (*p)[4] = ia; p != std::end(ia); ++p) { 
        for (int *q = (*p); q != std::end(*p); ++q) {
            std::cout << *q << " ";
        }
        std::cout << std::endl;
    }

    return 0;
}