將多個雙精度數四舍五入到小數點后兩位

Question

我是編程新手，我決定嘗試編寫這個程序，作為練習，最后它運行良好，沒有問題。

在第三條評論下方，我正在初始化一個執行計算的變量，在該語句之后，我將值四舍五入到小數點后兩位。 看着那段代碼塊，我將這兩行重復了 7 次，我想可能有更好的方法來縮短那段代碼。

double weightEarth, earthG, mercuryG, marsG, uranusG, venusG, saturnG, neptuneG, jupiterG;
            
//Assigning gravity force value corresponding to each planet
earthG = 9.81;
mercuryG = 3.7;
marsG = 3.711;
uranusG = 8.69;
venusG = 8.87;
saturnG = 10.44;
neptuneG = 11.15;
jupiterG = 24.79;

//Receive user input
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("This program will calculate how much you will weight on all planets");
Console.Write("Type in your weight in kg: ");
weightEarth = double.Parse(Console.ReadLine());

 //Calculating mass of object by dividing and gravitional force by multiplication
double weightMercury = (weightEarth / earthG) * mercuryG;
    weightMercury = Math.Round(weightMercury, 2);
double weightMars = (weightEarth / earthG) * marsG;
    weightMars = Math.Round(weightMars, 2);
double weightUranus = (weightEarth / earthG) * uranusG;
    weightUranus = Math.Round(weightUranus, 2);
double weightVenus = (weightEarth / earthG) * venusG;
    weightVenus = Math.Round(weightVenus, 2);
double weightSaturn = (weightEarth / earthG) * saturnG;
    weightSaturn = Math.Round(weightSaturn, 2);
double weightNeptune = (weightEarth / earthG) * neptuneG;
    weightNeptune = Math.Round(weightNeptune, 2);
double weightJupiter = (weightEarth / earthG) * jupiterG;
    weightJupiter = Math.Round(weightJupiter, 2);

Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine("\r\nYou weight:");
Console.WriteLine(weightMercury + "kg on Mercury");
Console.WriteLine(weightMars + "kg on Mars");
Console.WriteLine(weightUranus + "kg on Uranus");
Console.WriteLine(weightVenus + "kg on Venus");
Console.WriteLine(weightSaturn + "kg on Saturn");
Console.WriteLine(weightNeptune + "kg on Neptune");
Console.WriteLine(weightJupiter + "kg on Jupiter");

Console.ReadKey();

Answer 1

根據您想達到 go 的距離，您可以遵循一些概念。

第一個是不要重復自己 (DRY)。 您可以將權重計算提取到一種新方法中，例如，

private static double GetWeightForPlanet(double weightEarth, double earthG, double planetG)
{
      double weightPanet = (weightEarth / earthG) * planetG;
      weightPanet = Math.Round(weightPanet, 2);
      return weightPanet;
}

現在你的程序看起來像這樣，

//Calculating mass of object by dividing and gravitional force by multiplication
double weightMercury = GetWeightForPlanet(weightEarth, earthG, mercuryG);
double weightMars = GetWeightForPlanet(weightEarth, earthG, marsG);
double weightUranus = GetWeightForPlanet(weightEarth, earthG, uranusG);
double weightVenus = GetWeightForPlanet(weightEarth, earthG, venusG);
double weightSaturn = GetWeightForPlanet(weightEarth, earthG, saturnG);
double weightNeptune = GetWeightForPlanet(weightEarth, earthG, neptuneG);
double weightJupiter = GetWeightForPlanet(weightEarth, earthG, jupiterG);

Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine("\r\nYou weight:");
Console.WriteLine(weightMercury + "kg on Mercury");
Console.WriteLine(weightMars + "kg on Mars");
Console.WriteLine(weightUranus + "kg on Uranus");
Console.WriteLine(weightVenus + "kg on Venus");
Console.WriteLine(weightSaturn + "kg on Saturn");
Console.WriteLine(weightNeptune + "kg on Neptune");
Console.WriteLine(weightJupiter + "kg on Jupiter");

仍然有一些重復代碼，但我可以看到一些常見的數據模式。 也許數據結構會有所幫助； 讓我們介紹一下概念（類） Pl.net ，

public class Planet
{
    public string Name { get; set; }
    public double Gforce { get; set; }
}

您的代碼將如下所示，

double earthG = 9.81, weightEarth;

var planets = new List<Planet>
{
       new Planet { Name = "Mercury", Gforce = 3.7 },
       new Planet { Name = "Mars", Gforce = 3.711},
       new Planet { Name = "Uranus", Gforce = 8.69 },
       new Planet { Name = "Saturn", Gforce = 10.44 },
       new Planet { Name = "Neptune", Gforce = 11.15 },
       new Planet { Name = "Venus", Gforce = 8.87 },
       new Planet { Name = "Jupiter", Gforce = 24.79 }
};

//Receive user input
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("This program will calculate how much you will weight on all planets");
Console.Write("Type in your weight in kg: ");
weightEarth = double.Parse(Console.ReadLine());

Console.ForegroundColor = ConsoleColor.Blue;

Console.WriteLine("\r\nYou weight:");

foreach (var planet in planets)
{
     Console.WriteLine($"{GetWeightForPlanet(weightEarth, earthG, planet.Gforce)} kg on {planet.Name}");
}

我可以繼續前進，但可能會停在這里。 這僅用於演示目的，不適用於生產代碼。 善待代碼審查:)