++x和x++

class MainClass
{
    static void Main()
    {
        double x;

        x = 1.5;
        Console.WriteLine(++x);
        Console.WriteLine(x);

        x = 1.5;
        Console.WriteLine(x++);
        Console.WriteLine(x);
    }
}

结果值为：
2.5
2.5

1.5
2.5