Question

我的程序将计算区域，但我需要在它自己的方法中使用每个不同的形状，并且我很难理解如何首先将它们全部分离到它们自己的方法中并将它们全部链接在一起。非常感谢任何帮助。

import java.util.Scanner;
public class Project4 {

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        String s = "Please choose which area/volume to calculate: 1-Circle 2-Triangle 3-Cone 4-Cylinder 5-Sphere 6-Quit: ";
        System.out.print(s);
        System.out.println(" ");
        int num = keyboard.nextInt();
        if (num < 1 || num > 6){
            System.out.print("Please choose a number between 1 and 6: ");
            num = keyboard.nextInt();
        }
        if(num == 1){
            System.out.print("Please enter the radius: ");
            double r = keyboard.nextDouble();
            double a;
            a = 3.14 * r * r;
            System.out.print("The area of the circle is: " + a);
            System.out.println(" ");
            System.out.print(s);
            num = keyboard.nextInt();
        }
        if(num == 2){
            System.out.print("Please enter the base: ");
            double b = keyboard.nextDouble();
            double at;
            System.out.print("Please enter the height: ");
            double h = keyboard.nextDouble();
            at = .5 * b * h;
            System.out.print("The area of the triangle is: " + at);
            System.out.println(" ");
            System.out.print(s);
            num = keyboard.nextInt();
        }
        if(num == 3){
            System.out.print("Please enter the radius: ");
            double r = keyboard.nextDouble();
            System.out.print("Please enter the height: ");
            double h = keyboard.nextDouble();
            double v1;
            v1 = (1/3) * 3.14 * r * r * h;
            System.out.print("The volume of the cone is: " + v1);
            System.out.println(" ");
            System.out.print(s);
            num = keyboard.nextInt();
        }
        if(num == 4){
            System.out.print("Please enter the radius: ");
            double r = keyboard.nextDouble();
            System.out.print("Please enter the height: ");
            double h = keyboard.nextDouble();
            double vc;
            vc = 3.14 * r * r * h;
            System.out.print("The volume of the cylinder is: " + vc);
            System.out.println(" ");
            System.out.print(s);
            num = keyboard.nextInt();
        }
        if(num == 5){
            System.out.print("Please enter the radius: ");
            double r = keyboard.nextDouble();
            double vs;
            vs = (4/3) * 3.14 * r * r * r;
            System.out.print("The volume of the sphere is: " + vs);
            System.out.println(" ");
            System.out.print(s);
            num = keyboard.nextInt();
        }
        if(num == 6){
            System.out.print("Thank you for using this program");
        }

}
}

Answer 1

您可以使用switch..case

switch(num) {
  case 1: calculateCircleArea();
          break;
  case 2: calculateTriangleArea();
          break;
  case 3: calculateConeVolume();
          break;
  case 4: calculateCylinderVolume();
          break;
  case 5: calculateSphereVolume();
          break;
  case 6: System.out.print("Thank you for using this program");
          break;
  default: System.out.print("Please choose a number between 1 and 6: ");
           break;
}

Answer 2

您可以创建新的私有/公共方法来进行计算并将它们分开。

拿这个部分

if(num == 1){
    System.out.print("Please enter the radius: ");
    double r = keyboard.nextDouble();
    double a;
    a = 3.14 * r * r;
    System.out.print("The area of the circle is: " + a);
    System.out.println(" ");
    System.out.print(s);
    num = keyboard.nextInt();
}

您可以像这样为

创建一个新的计算方法

public static double getArea(double radius)
{
return 3.14*radius*radius;
}

然后，在if语句中你可以说

if(num == 1){
        System.out.print("Please enter the radius: ");
        double r = keyboard.nextDouble();
        double a;
        a = getArea(r);
        System.out.print("The area of the circle is: " + a);
        System.out.println(" ");
        System.out.print(s);
        num = keyboard.nextInt();
    }

在这种情况下，你会看到一个单行的方法，它并不是非常有用。但是你也可以拆分更广泛的计算，这只是一个例子。此外，您可以使用开关语句，而不是所有if-blocks，就像其他答案所示。

在Java中使用多种方法计算几何图形的面积

2 个答案: