php中那个函数中的return 0 return 1 return -1表示什么意思?请看代码
function cmp ($a, $b) {
if ($a == $b) {
return 0;
}
else if($a > $b){
return -1;
}
else{
return 1;
}
}
$a = array (4 => "four", 3 => "three", 20 => "twenty", 10 => "ten",11=>"four");
uksort ($a, "cmp");
while (list ($key, $value) = each ($a)) {
echo "$key: $value\n";
print "<br />";
}