<?php
$a=array(0=>array(),1=>array(),2=>array(),3=>array(),4=>array());
$a[0][0] = 0;
$a[0][1] = 1;
$a[0][2] = 2;
$a[1][0] = 3;
$a[1][1] = 4;
$a[1][2] = 5;
$a[2][3] = 6;
$a[2][4] = 7;
$a[2][5] = 8;
$a[3][0] = 9;
$a[4][0] = 10;
$a[4][1] = 11;
end($a);
$x=key($a);
echo "x=$x ";
end($a[$x]);
echo "y=".key($a[$x]);