C#中的乘法

Question

我是C#的新手,并尝试使用Switch进行乘法的以下程序.该程序完全通过Switch案例,但相乘的结果不会显示在控制台中.你能帮忙吗？

using System;

public class Program
{
 public static void Main(string[] args)
 {
    int _pLicense = 50;
    int _sLicense = 100;
    int _eLicense = 150;
    String lType;
    int nSeats;
Console.WriteLine("\n1.Personal License\n2.Startup License\n3.Enterprise License");
        Console.WriteLine("Enter the license type");
        lType = Console.ReadLine();
        //lType = char.Parse(Console.ReadLine());


switch(lType)
    {
        case "1":
            Console.WriteLine("Enter the number of seats");
            nSeats = int.Parse(Console.ReadLine());
            //Console.WriteLine(_pLicense);
            int Cost = _pLicense*nSeats;
            Console.WriteLine("Personal License Cost : $", +Cost);
            break;
        case "2":
            Console.WriteLine("Enter the number of seats");
            nSeats = int.Parse(Console.ReadLine());
            //Console.WriteLine(_sLicense);
            Cost = (_sLicense * nSeats);
            Console.WriteLine("Startup License Cost : $", Cost);
            break;
        case "3":
            Console.WriteLine("Enter the number of seats");
            nSeats = int.Parse(Console.ReadLine());
            //Console.WriteLine(_pLicense);
            Cost = (_eLicense * nSeats);
            Console.WriteLine("Enterprise License Cost : $", Cost);
            break;
        default:
        Console.WriteLine("Invalid Type");
           break;
    }
}

}

Answer 1

改变你Console.Writeline的

Console.WriteLine($"Personal License Cost : ${Cost}");

和

Console.WriteLine($"Enterprise License Cost : ${Cost}");

您也可以使用格式化成本{Cost:d}看https://docs.microsoft.com/en-us/dotnet/standard/base-types/composite-formatting.

建议您不要使用int.Parse,因为如果输入字符,它将引发错误.所以将代码改为类似的东西

if(int.TryParse(Console.ReadLine(), out int nSeats)
{
    Console.WriteLine($"Enterprise License Cost : ${Cost}");
}
else
{
    //Try again
}

您不必在顶部声明nSeats,它会处理错误.

这就是我编写代码的方式

public static void Main(string[] args)
{
    int nSeats = 0;
    Console.WriteLine("\n1.Personal License\n2.Startup License\n3.Enterprise License");
    Console.WriteLine("Enter the license type");
    var lType = Console.ReadLine();  //ReadLine returns a string, so it will automatically make lType a string
    int _LicenseCost = lType == "1" ? 50 : lType == "2" ? 100 : lType == "3" ? 150 : 0;
    if(_LicenseCost > 0)
    {
        while(true)
        {
            Console.WriteLine("Enter the number of seats");
            if(int.TryParse(Console.ReadLine(), out nSeats))
                break;
            else
                Console.WriteLine("Please enter a valid number");
        }
        Console.WriteLine((lType == "1" ? "Personal" : lType == "2" ? "Startup" : lType == "3" ? "Enterprise" : "") + $" License Cost : ${_LicenseCost * nSeats}");
    }
    else
        Console.WriteLine("License type is not valid. Good bye!");
}