控制台应用程序 C# 循环

Question

您好，我正在学习成为一名程序员，这是我正在从事的一个项目。控制台基本上接受用户输入（直径）并告诉您将获得多少个披萨片以及每片的面积。在告诉他们每个切片和面积后，它必须提示新的输入。切片是根据直径范围确定的，例如 12 - 20" 直径 = 8 个切片。用户必须输入 12" - 36" 之间的范围，否则会收到错误消息。此外，如果用户输入直径 36，它必须以 4 的减量显示所有其他切片，因此 24 , 20 , 16 ,12 , 8 ，但如果直径最终落在 8 以下。切片，因此 12 切片将显示 8 切片和 12 切片

最后，我们正在学习循环，我们将使用 do while 循环，

这就是我所拥有的 for 循环。但它不起作用

        //DECLARATIONS
        double circleArea;  // area of pizza
        double diameter; // diameter of the pizza
        double areaOfSlice; // area of the slices
        double radius; // half the diameter of the pizza
        double slices = 0; // number of pizza slices
        string message = ""; // a string to hold a message to the user
        const int DIAMETER_RANGE_MASSIVE = 36;
        const int DIAMETER_RANGE_EXTRA_LARGE = 30;
        const int DIAMETER_RANGE_LARGE = 24;
        const int DIAMETER_RANGE_MED = 16;
        const int DIAMETER_RANGE_LOW = 12; // Low end on range scale for diameter
        const int SLICES_LOW_DIAMETER = 8; // number of pizza slices based on diameter
        const int SLICES_MID_DIAMETER = 12; // number of pizza slices based on diameter
        const int SLICES_HIGH_DIAMETER = 16; // number of pizza slices based on diameter
        const int SLICES_GIANT_DIAMETER = 24; // number of pizza slices based on diameter        
        bool needInput = true;
        const int END_PROGRAM = 0;




        // INPUT
        // Prompt for and get keyboard input

        Console.Write("Please enter the diameter of your pizza (0 to end program): ");  // get user to input diameter
        diameter = Convert.ToDouble(Console.ReadLine()); // read a line of text (string) from the keyboard,
        // convert that string to an double,
        // assign the resulting value to diameter

        // PROCESSING
        // determine if diameter meets requirements of 12" to 36"
        // if does not meet requirements show error message and have user enter in new diameter
        do
        {
            if (diameter < DIAMETER_RANGE_LOW || diameter > DIAMETER_RANGE_MASSIVE)

            {
                message = "\nENTRY ERROR";
                message += "\nPizza must have a diameter in the range of 12” to 36” inclusive!";
                message += "\nPlease try again.";
            }



        else {    
            needInput = false;
                // determine the number of slices based on diameter


                if (diameter >= DIAMETER_RANGE_LOW && diameter < DIAMETER_RANGE_MED)
                {
                    slices = (SLICES_LOW_DIAMETER);
                }
                else if (diameter < DIAMETER_RANGE_LARGE)
                {
                    slices = (SLICES_MID_DIAMETER);
                }
                else if (diameter < DIAMETER_RANGE_EXTRA_LARGE)
                {
                    slices = (SLICES_HIGH_DIAMETER);
                }
                else
                {
                    slices = (SLICES_GIANT_DIAMETER);
                }

                Console.Clear(); // clears console to show new output lines
                //OUTPUT
                for (int slicesAddFour = 8; slicesAddFour <=slices; slicesAddFour+=4) // for each slices
                {
                // determine the area of the slices
                radius = diameter / 2; // uses diameter to get radius
                circleArea = Math.PI * Math.Pow(radius, 2); // uses math class to calculate circle area  
                areaOfSlice = Math.Round((circleArea / slices), 2); // divides circle area by slices, takes the result of above calculation and rounds

                Console.WriteLine("\nA {0}\" Pizza diameter: {0}\".", diameter); 
                message +=("\n==============================================");
                Console.WriteLine("\nCut in {0} slices results in an area of {1}\" per slice.",areaOfSlice,slices);

                }


        } //end of else

            message = ("\nPlease enter the diameter of your pizza (0 to end program)");
            needInput = true;
        } while (diameter != END_PROGRAM && needInput);
    }
}

。

Answer 1

您的问题是您读入一次数据，然后继续循环而没有获取任何新数据。如果您移动到

Console.Write("Please enter the diameter of your pizza (0 to end program): ");  // get user to input diameter
diameter = Convert.ToDouble(Console.ReadLine()); // read a line of text (string) from the keyboard,

循环内部，它应该可以解决您的问题

Answer 2

移动这两行：

Console.Write("Please enter the diameter of your pizza (0 to end program): ");  // get user to input diameter
            diameter = Convert.ToDouble(Console.ReadLine()); // read a line of text (string) from the keyboard,

在其中的 do/while 循环内部。

你的代码变成：

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

namespace SOHelp
{
    class Program
    {
        static void Main(string[] args)
        {
              //DECLARATIONS
        double circleArea;  // area of pizza
        double diameter; // diameter of the pizza
        double areaOfSlice; // area of the slices
        double radius; // half the diameter of the pizza
        double slices = 0; // number of pizza slices
        string message = ""; // a string to hold a message to the user
        const int DIAMETER_RANGE_MASSIVE = 36;
        const int DIAMETER_RANGE_EXTRA_LARGE = 30;
        const int DIAMETER_RANGE_LARGE = 24;
        const int DIAMETER_RANGE_MED = 16;
        const int DIAMETER_RANGE_LOW = 12; // Low end on range scale for diameter
        const int SLICES_LOW_DIAMETER = 8; // number of pizza slices based on diameter
        const int SLICES_MID_DIAMETER = 12; // number of pizza slices based on diameter
        const int SLICES_HIGH_DIAMETER = 16; // number of pizza slices based on diameter
        const int SLICES_GIANT_DIAMETER = 24; // number of pizza slices based on diameter        
        bool needInput = true;
        const int END_PROGRAM = 0;




        // INPUT
        // Prompt for and get keyboard input


        // convert that string to an double,
        // assign the resulting value to diameter

        // PROCESSING
        // determine if diameter meets requirements of 12" to 36"
        // if does not meet requirements show error message and have user enter in new diameter
        string message = "Please enter the diameter of your pizza (0 to end program): ";

        do
        {
            Console.Write(message);  // get user to input diameter
            diameter = Convert.ToDouble(Console.ReadLine()); // read a line of text (string) from the keyboard,

            if (diameter < DIAMETER_RANGE_LOW || diameter > DIAMETER_RANGE_MASSIVE)

            {
                message = "\nENTRY ERROR";
                message += "\nPizza must have a diameter in the range of 12” to 36” inclusive!";
                message += "\nPlease try again.";
            }



        else {    
            needInput = false;
                // determine the number of slices based on diameter


                if (diameter >= DIAMETER_RANGE_LOW && diameter < DIAMETER_RANGE_MED)
                {
                    slices = (SLICES_LOW_DIAMETER);
                }
                else if (diameter < DIAMETER_RANGE_LARGE)
                {
                    slices = (SLICES_MID_DIAMETER);
                }
                else if (diameter < DIAMETER_RANGE_EXTRA_LARGE)
                {
                    slices = (SLICES_HIGH_DIAMETER);
                }
                else
                {
                    slices = (SLICES_GIANT_DIAMETER);
                }

                Console.Clear(); // clears console to show new output lines
                //OUTPUT
                for (int slicesAddFour = 8; slicesAddFour <=slices; slicesAddFour+=4) // for each slices
                {
                // determine the area of the slices
                radius = diameter / 2; // uses diameter to get radius
                circleArea = Math.PI * Math.Pow(radius, 2); // uses math class to calculate circle area  
                areaOfSlice = Math.Round((circleArea / slices), 2); // divides circle area by slices, takes the result of above calculation and rounds

                Console.WriteLine("\nA {0}\" Pizza diameter: {0}\".", diameter); 
                message +=("\n==============================================");
                Console.WriteLine("\nCut in {0} slices results in an area of {1}\" per slice.",areaOfSlice,slices);

                }


        } //end of else

            message = ("\nPlease enter the diameter of your pizza (0 to end program)");
            needInput = true;
        } while (diameter != END_PROGRAM && needInput);
    }
}
        }

Answer 3

using System;

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

namespace Lab6B
{
    class Program
    {
        static void Main(string[] args)
        {
            //DECLARATIONS
            double circleArea;  // area of pizza
            double diameter; // diameter of the pizza
            double areaOfSlice; // area of the slices
            double radius; // half the diameter of the pizza
            double slices = 0; // number of pizza slices
            const int INPUT_MAX = 36; // maximum entry for diameter
            const int DIAMETER_RANGE_EXTRA_LARGE = 30; // diameter range used to figure out slices
            const int DIAMETER_RANGE_LARGE = 24; // diameter range used to figure out slices
            const int DIAMETER_RANGE_MED = 16; // diameter range used to figure out slices
            const int INPUT_MIN = 12; // minimum entry for diameter
            const int SLICES_LOW_DIAMETER = 8; // number of pizza slices based on diameter
            const int SLICES_MID_DIAMETER = 12; // number of pizza slices based on diameter
            const int SLICES_HIGH_DIAMETER = 16; // number of pizza slices based on diameter
            const int SLICES_GIANT_DIAMETER = 24; // number of pizza slices based on diameter        
            bool needInput = true; // does the program need input true or false
            const int END_PROGRAM = 0; // 0 ends the program





            // INPUT
            // Prompt for and get keyboard input

            Console.Write("Please enter the diameter of your pizza: ");  // get user to input diameter
            diameter = Convert.ToDouble(Console.ReadLine()); // read a line of text (string) from the keyboard, 

            // convert that string to an double,
            // assign the resulting value to diameter

            while (diameter != END_PROGRAM && needInput) // Begin while loop

            {

                // PROCESSING

                // determine if diameter meets requirements of 12" to 36"
                // if does not meet requirements show error message and have user enter in new diameter


                if (diameter < INPUT_MIN || diameter > INPUT_MAX)
                {

                    Console.WriteLine( "\nENTRY ERROR\nPizza must have a diameter in the range of 12” to 36” inclusive!\nPlease try again.");
                }


                else
                {
                    needInput = false;
                    // determine the number of slices based on diameter


                    if (diameter < DIAMETER_RANGE_MED)
                    {
                        slices = (SLICES_LOW_DIAMETER);
                    }
                    else if (diameter < DIAMETER_RANGE_LARGE)
                    {
                        slices = (SLICES_MID_DIAMETER);
                    }
                    else if (diameter < DIAMETER_RANGE_EXTRA_LARGE)
                    {
                        slices = (SLICES_HIGH_DIAMETER);
                    }
                    else
                    {
                        slices = (SLICES_GIANT_DIAMETER);
                    }

                    Console.Clear(); // clears console to show new output lines

                    //OUTPUT

                    Console.WriteLine("\nA {0}\" Pizza diameter: {0}\".", diameter);
                    Console.WriteLine("\n==============================================");

                    for (int slicesAddFour = 8; slicesAddFour <= slices; slicesAddFour += 4) // for each slices
                    {
                        // determine the area of the slices
                        radius = diameter / 2; // uses diameter to get radius
                        circleArea = Math.PI * Math.Pow(radius, 2); // uses math class to calculate circle area  
                        areaOfSlice = Math.Round((circleArea / slicesAddFour), 2); // divides circle area by slices, takes the result of above calculation and rounds


                        Console.WriteLine("\nCut in {0} slices results in an area of {1}\" per slice.", slicesAddFour, areaOfSlice);


                    }


                } //end of else

                Console.Write("\nPlease enter the diameter of your pizza (0 to exit): ");
                diameter = Convert.ToDouble(Console.ReadLine());
                Console.Clear(); // clears console to show new output lines

                // set the need input value back to true for new entry
                needInput = true;

             } // end of while loop
        }
    }
}