Programming PHP, 3rd Edition

Multidimensional Arrays

The values in an array can themselves be arrays. This lets you easily create multidimensional arrays:

$row0 = array(1, 2, 3);
$row1 = array(4, 5, 6);
$row2 = array(7, 8, 9);
$multi = array($row0, $row1, $row2);

You can refer to elements of multidimensional arrays by appending more []s:

$value = $multi[2][0];                 // row 2, column 0. $value = 7

To interpolate a lookup of a multidimensional array, you must enclose the entire array lookup in curly braces:

echo("The value at row 2, column 0 is {$multi[2][0]}\n");

Failing to use the curly braces results in output like this:

The value at row 2, column 0 is Array[0]