如何强制重复条目

Question

这段代码对我有用，除了它只检查一次重复项，如果用户再次输入相同的整数，程序将第二次接受它。如何使该程序不接受该条目，无论用户输入多少次？

        int[] shippedOrderNumbers = new int[5];
        Console.WriteLine("Please Input first Shipping Number: ");
        shippedOrderNumbers[0] = Convert.ToInt32(Console.ReadLine());           
        Console.WriteLine("Please Input second Shipping Number: ");
        shippedOrderNumbers[1] = Convert.ToInt32(Console.ReadLine());           

        if (shippedOrderNumbers[0] == shippedOrderNumbers[1])
        {
            Console.WriteLine("A dublicate number is not allowed please try again: ");
            shippedOrderNumbers[1] =Convert.ToInt32(Console.ReadLine());               
        }          
            Console.WriteLine("Please Input third Shipping Number: ");
            shippedOrderNumbers[2] = Convert.ToInt32(Console.ReadLine());

        if (shippedOrderNumbers[0] == shippedOrderNumbers[2] || shippedOrderNumbers[1] == shippedOrderNumbers[2])
        {
            Console.WriteLine("A dublicate number is not allowed please try again: ");
            shippedOrderNumbers[2] = Convert.ToInt32(Console.ReadLine());
        }                           
            Console.WriteLine("Please Input fourth Shipping Number: ");
            shippedOrderNumbers[3] = onvert.ToInt32(Console.ReadLine());               

        if (shippedOrderNumbers[0] == shippedOrderNumbers[3] || shippedOrderNumbers[1] == shippedOrderNumbers[3] || shippedOrderNumbers[2] == shippedOrderNumbers[3])
        {
            Console.WriteLine("A dublicate number is not allowed please try again: ");
            shippedOrderNumbers[3] = Convert.ToInt32(Console.ReadLine());
        }                           
            Console.WriteLine("Please Input fifth Shipping Number: ");
            shippedOrderNumbers[4] = Convert.ToInt32(Console.ReadLine());

        if (shippedOrderNumbers[0] == shippedOrderNumbers[4] || shippedOrderNumbers[1] == shippedOrderNumbers[4] || shippedOrderNumbers[2] == shippedOrderNumbers[4] || shippedOrderNumbers[3] == shippedOrderNumbers[4])
        {
            Console.WriteLine("A dublicate number is not allowed please try again: ");
            shippedOrderNumbers[4] = Convert.ToInt32(Console.ReadLine());
        }           

Answer 1

我认为使用通用列表而不是数组会更好。还可以使用简单循环来简化代码。有关示例，请参阅以下内容。

IList<int> shippedOrderNumbers = new List<int>();
for (int = 0; i < 5; i++)
{
    Console.WriteLine("Please input the Shipping Number: ");
    int shippingNumber;
    if (!Int.TryParse(Console.ReadLine(), out shippingNumber) 
    {
        Console.WriteLine("Your shipping number is not an integer");
    }
    if (shippedOrderNumbers.Contains(shippingNumber)) 
    {
        Console.WriteLine("This shipping number has already been entered.");
    }
    else 
    {
        shippedOrderNumbers.Add(shippingNumber);
        Console.WriteLine("Thanks for submitting your shipping number.");
    }
}

附言。我在记事本中写了这个，所以它可能不起作用，但应该为您提供有关如何解决问题的一般指南。

Answer 2

沿着这些思路应该这样做：

var shippedOrderNumbers = new List<int>();
var validOrderNumbers = 0;
while(validOrderNumbers < 5)
{
     Console.WriteLine("Input order number:");
     var nextOrderNumber = Convert.ToInt32(Console.ReadLine());
     if(shippedOrderNumbers.Any(son => son == nextOrderNumber))
     {
         Console.WriteLine("Duplicate order number. Please enter another");
         continue;
     }
     shippedOrderNumbers.Add(nextOrderNumber);
     validOrderNumbers++;
}