function myfunction($v1, $v2) {
if ($v1 == $v2) {
return 0;
}
if ($v1 > $v2) {
return 1;
} else {
return-1;
}
}
$a1 = array(5 => "Rat", 2 => "Cat", 7 => "Horse");
$a2 = array(8 => "Rat",4 => "Cat",7 => "Horse");
print_r(array_diff_uassoc($a1, $a2, "myfunction"));
它是如何执行的?