function array_display($array, $pre=FALSE) {
$tag = $pre ? 'pre' : 'p';
printf("<%s>%s\n", $tag, var_export($array, TRUE), $tag);
}
$dogs1 = array('A' => 'C', 'B' => 'C', 'D' => 'C');
$dogs2 = array('a' => 'a', 'b' => 'b');
array_display(array_merge($dogs1, $dogs2), TRUE);
array_display($dogs1 + $dogs2, TRUE);
?>