Not-so-obvious PHP behavior when using for-each by reference and value with same variable name. (contrived example)

php_reference_bug.php

<?php
$foo = array(1, 2, 3);

foreach($foo as &$bar) {
	$bar *= $bar;
}

foreach($foo as $bar){
	echo "The square is ", $bar, "\n";
}

// Output:
// The square is 1
// The square is 4
// The square is 4

?>