C++访问二维数组

#include <iostream>

using namespace std;

int main () {
   // an array with 5 rows and 2 columns.
   int a[5][2] = { {0,0}, {1,2}, {2,4}, {3,6},{4,8}};

   // output each array element's value                      
   for ( int i = 0; i < 5; i++ )
      for ( int j = 0; j < 2; j++ ) {

         cout << a[ << i << ][ << j << ]: ;
         cout << a[i][j]<< endl;
      }

   return 0;
}