Question

我正在编写一个数组教程。我对阵列的了解有限。我遇到一个错误“operator'+ ='不能应用于'double []'类型的操作数。我不知道为什么这不起作用。原始代码正常工作，直到教程要求使用数组进行更改。想法？

没有数组的原始代码：

string inputString;
        double sales=0, totalA = 0, totalB = 0, totalC=0;
        double total = 0;
        string initial;

        Console.Write("Enter family initial: ");
        inputString = Console.ReadLine();
        initial = inputString.ToString();

        while (initial != "z" && initial != "Z")
        {
            Console.Write("Enter a sales amount: ");
            inputString = Console.ReadLine();
            sales = Convert.ToDouble(inputString);
            total += sales;

            if (initial == "A")
            {
                totalA += sales;
            }
            else if (initial == "B")
            {
                totalB += sales;
            }
            else if (initial == "C")
            {
                totalC += sales;
            }


            Console.Write("Enter family initial: ");
            inputString = Console.ReadLine();
            initial = inputString.ToString();

        }
        Console.WriteLine("Family A earned: {0}", totalA.ToString("C"));
        Console.WriteLine("Family B earned: {0}", totalB.ToString("C"));
        Console.WriteLine("Family C earned: {0}", totalC.ToString("C"));
        Console.WriteLine("Grand Total Sales: {0}",total.ToString("c"));

这是我尝试修改代码（按请求）以在数组中存储首字母和累计总销售额值。我能做些什么来实现这个目标？

string inputString;
// double sales=0, totalA = 0, totalB = 0, totalC=0;
double sales;
double total = 0;
string initial;

string[] familyNames = {"Anderson","Bowman","Claxton"};
string[] inital = { "A", "B", "C" };
double[] totalA, totalB, totalC;

Console.Write("Enter family initial: ");
inputString = Console.ReadLine();
initial = inputString.ToString();

while (initial != "z" && initial != "Z")
{
    Console.Write("Enter a sales amount: ");
    inputString = Console.ReadLine();
    sales = Convert.ToDouble(inputString);
    total += sales;




    if (initial == "A")
    {
        totalA += sales;
    }
    else if (initial == "B")
    {
        totalB += sales;
    }
    else if (initial == "C")
    {
        totalC += sales;
    }


    Console.Write("Enter family initial: ");
    inputString = Console.ReadLine();
    initial = inputString.ToString();

}
Console.WriteLine("Family A earned: {0}", totalA.ToString("C"));
Console.WriteLine("Family B earned: {0}", totalB.ToString("C"));
Console.WriteLine("Family C earned: {0}", totalC.ToString("C"));
Console.WriteLine("Grand Total Sales: {0}",total.ToString("c"));

Answer 1

以下行有问题

totalA += sales;
totalB += sales;
totalC += sales;

因为totalA / totalB / totalC被声明为双数组。

分析你的代码之后，我觉得你还不需要双数组。因此，要纠正此问题，您需要更改以下内容

double[] totalA, totalB, totalC;

到

double totalA = 0;
double totalB = 0;
double totalC = 0;

Answer 2

由于这是您正在关注的教程，我认为本练习的目的是消除3个total变量并改为使用数组。

因此，您只需拥有一个3元素数组totalA，而不是totalB，totalC和totals。也许是这样的：

string inputString;
double sales;
double total = 0;
string initial;

string[] familyNames = {"Anderson","Bowman","Claxton"};
string[] inital = { "A", "B", "C" };
double[] totals = new double[3];

Console.Write("Enter family initial: ");
inputString = Console.ReadLine();
initial = inputString.ToString();

while (initial != "z" && initial != "Z")
{
    Console.Write("Enter a sales amount: ");
    inputString = Console.ReadLine();
    sales = Convert.ToDouble(inputString);
    total += sales;

    if (initial == "A")
    {
        totals[0] += sales;
    }
    else if (initial == "B")
    {
        totals[1] += sales;
    }
    else if (initial == "C")
    {
        totals[2] += sales;
    }


    Console.Write("Enter family initial: ");
    inputString = Console.ReadLine();
    initial = inputString.ToString();

}
Console.WriteLine("Family A earned: {0}", totals[0].ToString("C"));
Console.WriteLine("Family B earned: {0}", totals[1].ToString("C"));
Console.WriteLine("Family C earned: {0}", totals[2].ToString("C"));
Console.WriteLine("Grand Total Sales: {0}",total.ToString("c"));

有一些方法可以对此进行优化，例如使用循环打印总计，但我会留给您。

Answer 3

+运算符不适用于数组。例如：

double[] array = new double[2];
array = array + 2; //// this is undefined.

在你的情况下，是totalA，totalB，totalC double（值）还是double[]（数组）？

无法添加到阵列

3 个答案: