c# 兩個數的加減乘除

Console.Title = "加減乘除";

double x, y,z=0;
string m;
int n=0;
Console.WriteLine("第一個數：");
x = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("運算符(默認為加)：");
m =Console.ReadLine();
m = (m == "加" || m == "+") ? "加" : (m == "減" || m == "-") ? "減" : (m == "乘" || m == "*"||m=="×") ? "乘" : (m == "除" || m == "/"||m=="÷") ? "除":"加" ;
Console.WriteLine("進行的是" + m + "法運算");
Console.WriteLine("第二個數：");
y = Convert.ToDouble(Console.ReadLine());

switch (m)
{
case "加":

z = x + y;
break;
case "減":

z = x - y;
break;
case "乘":

z = x * y;
break;
case "除":

z = x / y;
break;
default:

z = x + y;
break;
}

Console.WriteLine("運算結果是"+z);

Console.ReadKey();