Question

我的错误消息说“无法将类型double转换为int []”，与string和int相同（最后，arraySalsa）我理解为什么，但我是不确定如何修复所以到目前为止数组将全部带入。你能帮忙吗？

class Program
{
    static void Main(string[] args)
    {
        string[] heat = new string[] { "Mild", "Medium", "Hot", "Super Hot", "Scorching" };
        double[] price = new double[4];
        int[] numSold = new int[4];

        int counter;
        {
            for (counter = 0; counter != heat.Length; counter++)
            {
                Console.WriteLine("What do you wish to charge for " + heat[counter] + " ?");
                price[counter] = Convert.ToDouble(Console.ReadLine());
                Console.WriteLine("How many jars of " + heat[counter] + " did you sell last year?");
                numSold[counter] = Convert.ToInt32(Console.ReadLine());
            }//end forloop

        } 

        for (int count = 0; count < heat.Length; count++)
        {
            Console.WriteLine("You sold " + numSold[count] + " of " + heat[count] + " at $" + price[count] + " each.");
        }//end forloop

        Array[,,] arraySalsa;
        arraySalsa = new Array[heat, price, numSold];
    }
}

Answer 1

正如我的评论中所提到的，你应该使用一个类，而不是一个多维数组。

class Program
{
    static void Main(string[] args)
    {
        var measurements = new Measurements();
        measurements.Heat = new string[] 
            { "Mild", "Medium", "Hot", "Super Hot", "Scorching" }.ToList(); 
        measurements.Price = new List<double>(4);
        measurements.NumSold = new List<int>(4);

        int counter;
        {
            for (counter = 0; counter != measurements.Heat.Count; counter++)
            {
                Console.WriteLine("What do you wish to charge for " + 
                    measurements.Heat[counter] + " ?");
                measurements.Price[counter] = Convert.ToDouble(Console.ReadLine());
                Console.WriteLine("How many jars of " + measurements.Heat[counter] + 
                    " did you sell last year?");
                measurements.NumSold[counter] = Convert.ToInt32(Console.ReadLine());
            }
        } 

        for (int count = 0; count < measurements.Heat.Count; count++)
        {
            Console.WriteLine("You sold " + measurements.NumSold[count] + " of " + 
                measurements.Heat[count] + " at $" + measurements.Price[count] 
                + " each.");
        }

        // your arraySalsa is now just your measurements instance
    }
}

public class Measurements
{
    public List<string> Heat { get; set; }
    public List<double> Price { get; set; }
    public List<int> NumSold { get; set; }
}

在C＃中使用列表而不是数组有很多好处，即使在进行简单索引时也是如此。由于它们是为您动态调整大小的，因此您不必担心增加上限。此外，您可以使用强大的LINQ方法来帮助您更轻松地操作集合。如果可能（除非您有极端的性能考虑因素），您应该始终倾向于列表。

或者，您可以创建一个包含三个属性中每个属性的Measurement类，并创建该类的集合，以清理所有索引操作。

class Program
{
    static void Main(string[] args)
    {
        var measurements = new List<Measurement>();
        var heat = new string[] 
            { "Mild", "Medium", "Hot", "Super Hot", "Scorching" }.ToList(); 

        int counter;
        {
            for (counter = 0; counter != heat.Count; counter++)
            {
                var measurement = new Measurement() { Heat = heat[counter]};
                Console.WriteLine("What do you wish to charge for " +
                    measurement.Heat + " ?");
                measurement.Price = Convert.ToDouble(Console.ReadLine());
                Console.WriteLine("How many jars of " + measurement.Heat + 
                    " did you sell last year?");
                measurement.NumSold = Convert.ToInt32(Console.ReadLine());
                measurements.Add(measurement);
            }
        }

        measurements.ForEach(x =>
        {
            Console.WriteLine("You sold " + x.NumSold + " of "
                + x.Heat + " at $" + x.Price + " each.");
        });
    }
}

public class Measurement
{
    public string Heat { get; set; }
    public double Price { get; set; }
    public int NumSold { get; set; }
}

Answer 2

如果你想在数组（或List或其他）中存储不同的类型，并且它们没有公共基类，那么你需要将它们存储为盒装对象。

var salsa = new object[20];
salsa[0] = 1;
salsa[1] = 42.42;
salsa[3] = "hot";

阅读它们你需要做的

var s1 = salsa[1];
if (s1 is int)
  Console.WriteLine((int)s1);
if(s1 is double)
  COnsole.WriteLine((double)s1);
etc...

请参阅How to unbox from object to type it contains, not knowing that type at compile time?

Answer 3

一种选择是使用object s：

的数组

object[] arraySalsa;
arraySalsa = new object[] {(object)heat, (object)price, (object)numSold};

如果需要，可以省略类型转换操作符(object)，编译器会推断它应该进行类型转换：

object[] arraySalsa;
arraySalsa = new object[] {heat, price, numSold};

然而，使用object[]可能是不好的做法，因为只给出了object[]类型，你不知道它中包含什么，编译器不会停止你不小心把错误的东西放在里面。因此，使用Tuple：

可能更好

Tuple<string[], double[], int[]> tupleSalsa;
tupleSalsa = new Tuple<string[], double[], int[]>(heat, price, numSold);

为方便起见，您可以使用Tuple.Create代替new Tuple<string[], double[], int[]>，这样您就不必再次写出该类型了：

Tuple<string[], double[], int[]> tupleSalsa;
tupleSalsa = Tuple.Create(heat, price, numSold);

Answer 4

创建多个类型数组的漏洞思路是错误的（打破数据一致性）。如果你按照建议使用对象，你将有很多拳击/拆箱来做后者。我建议创建一个具有3个属性的类产品：温度，价格，数量和数量。使用产品清单......

输出具有多个返回类型的数组c＃

4 个答案: