Question

我意识到我可以将我的数据放在构造函数调用的方法中，并且它可以工作。但是，我只是搞乱了一些代码，我正在尝试使用其他方法进行计算。这是书中的一个问题，因为我没有一个教师会在几周内发现错误，我想我会问这里。

有什么输入？拜托，谢谢

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace ConsoleApplication305
{
class Program
{
    static void Main(string[] args)
    {
        Trip a = new Trip();
        Console.WriteLine(a);

    }

    class Trip
    {
        int distanceTraveled;
        double costGas;
        int numberGallon;
        int mpg;
        double cpm;

        public int DistanceTraveled
        {
            get
            {
                return distanceTraveled;
            }
        }
        public double CostGas
        {
            get
            {
                return costGas;
            }
        }
        public int NumberGallon
        {
            get
            {
                return numberGallon;
            }
        }

        public Trip()
        {
            distanceTraveled = 312;
            costGas = 3.46;
            numberGallon = 10;

        }

        public void milesPerGal()
        {
            mpg = distanceTraveled / numberGallon;
        }

        public void costPerMile()
        {
            cpm = costGas * mpg;
        }

        public override string ToString()
        {
            return String.Format("The distance traveled is...{0} \nThe cost per gallon of gasoline is... {1} \nThe amount of gallons were... {2} \nThe miles per gallon attained were... {3} \nThe cost per MPG were... {4}", distanceTraveled, costGas, numberGallon, mpg, cpm);
        }
    }
}

}

Answer 1

IF 我理解你的问题，这应该适合你：

class Trip
{
    int distanceTraveled;
    double costGas;
    int numberGallon;
    int mpg;
    double cpm;

    public int DistanceTraveled
    {
        get
        {
            return distanceTraveled;
        }
    }
    public double CostGas
    {
        get
        {
            return costGas;
        }
    }
    public int NumberGallon
    {
        get
        {
            return numberGallon;
        }
    }

    public Trip()
    {
        distanceTraveled = 312;
        costGas = 3.46;
        numberGallon = 10;
        mpg = milesPerGal();
        cpm = costPerMile();
    }

    public int milesPerGal()
    {
        return distanceTraveled / numberGallon;
    }

    public double costPerMile()
    {
        return costGas * mpg;
    }

    public override string ToString()
    {
        return String.Format("The distance traveled is...{0} \nThe cost per gallon of gasoline is... {1} \nThe amount of gallons were... {2} \nThe miles per gallon attained were... {3} \nThe cost per MPG were... {4}", distanceTraveled, costGas, numberGallon, mpg, cpm);
    }
}

Answer 2

老实说，这里的一切都很好。由于您从未调用方法milesPerGal或costPerMile，因此私有变量mpg和cpm的值仍为0，也将输出。

你可能想要的是这个构造函数：

public Trip()
{
    distanceTraveled = 312;
    costGas = 3.46;
    numberGallon = 10;
    milesPerGal();
    costPerMile();
}

为了使这段代码按预期工作，我建议你使用这样的正确的getter和setter：

class Trip
{
    public int DistanceTraveled { get; set; }
    public double CostGas { get; set; }
    public int NumberGallon { get; set; }
    public int MilesPerGallon { get { return (NumberGallon != 0) ? DistanceTraveled / NumberGallon : 0; } }
    public double CostPerMile { get { return CostGas * MilesPerGallon; } }

    public Trip()
    {
        DistanceTraveled = 312;
        CostGas = 3.46;
        NumberGallon = 10;
    }

    public override string ToString()
    {
        return String.Format("The distance traveled is...{0} \nThe cost per gallon of gasoline is... {1} \nThe amount of gallons were... {2} \nThe miles per gallon attained were... {3} \nThe cost per MPG were... {4}", DistanceTraveled, CostGas, NumberGallon, MilesPerGallon, CostPerMile);
    }
}

请注意，使用此方法，每当您更新具有setter（DistanceTraveled，CostGas和NumberGallons）的任何字段时，相应的派生值（MilesPerGallon并且CostPerMile）将自动更正，无需任何其他方法调用，因为当有人访问这些字段时，它们是即时计算的。

其他不起作用的方法？

2 个答案: