PHP的引用传值

function change_value($num){
    $num+=2;
}
$age = 3;
change_value(&$age);
echo $age;


CS的引用传值

static void Main(string[] args)
{
    int age = 3;
    Console.WriteLine(change_value(ref age));
}
static int change_value(ref int num)
{
    num += 2;
    return num;
}