如何确保仅在 while 循环中满足 if 语句时才打印特定行答案

【问题标题】：How can I make sure that a certain line is printed only when the if statement is met in a while-loop如何确保仅在 while 循环中满足 if 语句时才打印特定行
【发布时间】：2019-10-12 15:53:17
【问题描述】：

我正在尝试打印 if 语句，但前提是值正确且符合要求。但是，if 语句位于 while 循环内，即使它要求用户在 if 语句中的值不正确时重试，它仍然会打印出用户第一次在 if 之外的 WriteLine 中输入的数字声明（它说模拟）。我希望它要求用户再试一次，直到值符合 if 语句的要求标准。

namespace Woodchuck
{
    class Program
    {
        static void Main(string[] args)
        {
            string restart = "Y";


            while (restart == "Y")
            {
                int totalWoodChucks = 0;
                int days = 0;

                const int MAXDAYS = 10;
                const int MINDAYS = 1;
                const int MAXWOOD = 100;
                const int MINWOOD = 1;


                Write("Enter number of woodchucks for this simulation (1-100): ");
                int.TryParse(ReadLine(), out totalWoodChucks);

                if (totalWoodChucks > MAXWOOD || totalWoodChucks < MINWOOD)
                {
                    WriteLine("Please try again");
                }


                Write("Enter number of days for this simulation (1-10): ");
                int.TryParse(ReadLine(), out days);
                if (days > MAXDAYS || days < MINDAYS)
                {
                    WriteLine("Please try again");
                }


                WriteLine($"SIMULATION 1: {totalWoodChucks} woodchucks over {days} days");

                Write("\nTo run another simulation, enter 'Y':");
                restart = ReadLine().ToUpper();

            }
            //Debug pause
            WriteLine("Press any key to wrap it up...");
        }
    }
}

【问题讨论】：

标签： c# if-statement while-loop

【解决方案1】：

字符串重启 = "Y";

    while(restart == "Y")
    {
        int totalWoodChucks = 0;
        int days = 0;

        const int MAXDAYS = 10;
        const int MINDAYS = 1;
        const int MAXWOOD = 100;
        const int MINWOOD = 1;


        Write("Enter number of woodchucks for this simulation (1-100): ");
        int.TryParse(ReadLine(), out totalWoodChucks);
        Write("Enter number of days for this simulation (1-10): ");
        int.TryParse(ReadLine(), out days);

        if((totalWoodChucks > MAXWOOD || totalWoodChucks < MINWOOD) &&(days > MAXDAYS || days < MINDAYS))
        {
            WriteLine("Please try again");
            continue;
        }

        WriteLine($"SIMULATION 1: {totalWoodChucks} woodchucks over {days} days");

        Write("\nTo run another simulation, enter 'Y':"); 
        restart = ReadLine().ToUpper();

    }
    //Debug pause
    WriteLine("Press any key to wrap it up...");

我所做的是在收集完所有数据后进行检查。然后如果数据不符合要求，它将再次要求再次尝试，直到数据满足为止。

【讨论】：

【解决方案2】：

您可以通过使用 while 循环来做到这一点，直到满足所需的条件。

这里有一个简单的例子来说明如何做到这一点：

int totalWoodChucks = 0;
int days = 0;

const int MAXDAYS = 10;
const int MINDAYS = 1;
const int MAXWOOD = 100;
const int MINWOOD = 1;

bool validWoodChucks = false;
while(!validWoodChucks)
{
    Console.Write("Enter number of woodchucks for this simulation (1-100): ");
    int.TryParse(Console.ReadLine(), out totalWoodChucks);

    if(totalWoodChucks > MAXWOOD || totalWoodChucks < MINWOOD)
    {
        Console.WriteLine("Invalid woodchucks. Please try again.");
    }
    else
    {
        validWoodChucks = true;
    }

}

bool validDays = false;
while(!validDays)
{
    Console.Write("Enter number of days for this simulation (1-10): ");
    int.TryParse(Console.ReadLine(), out days);
    if (days > MAXDAYS || days < MINDAYS)
    {
        Console.WriteLine("Invalid days. Please try again.");
    }
    else
    {
        validDays = true;
    }
}


Console.WriteLine("Wood chucks: " + totalWoodChucks);
Console.WriteLine("Days: " + days);

Console.ReadLine();

使用示例：

Enter number of woodchucks for this simulation (1-100): -10
Invalid woodchucks. Please try again.
Enter number of woodchucks for this simulation (1-100): 50
Enter number of days for this simulation (1-10): 20
Invalid days. Please try again.
Enter number of days for this simulation (1-10): 10
Wood chucks: 50
Days: 10

【讨论】：