Zool! Arty Workshop

What do you think the following code snippet prints?

// Fill the array (each array element has the same value as a key)
foreach(array('07', '08', '09', '10') as $n){
    $a[$n] = $n;
}

// Delete the first element from the array
array_shift($a);

// Print a value of the element with a key of '10'
echo $a['10'];

If you, like me, think that the element of the array with a key of '10' has a string value of "10", then you're unfortunately wrong. But now you've got a reason to read the article further.