java - 为什么我的函数总是无法通过我的 JUnit 测试？

Question

这是我正在测试的类(class)之一。它总是使 calculateVolume() 方法失败，我不确定为什么。

   package shape3D;


public class Sphere implements Cloneable {
    private double myRadius;
    private double myVolume;
    private double mySurfaceArea;
    private final static double pi = 3.14;

    public static void main(String args[]){
        Sphere sphere = new Sphere();
    }
    public double calculateVolume(){
        myVolume = (4/3)*pi*(Math.pow(myRadius,3));
        return myVolume;
    }
     public double calculateSurfaceArea(){
         mySurfaceArea = ((4)*(pi)*(Math.pow(myRadius,2)));
         return mySurfaceArea;
     }
     public double getSurfaceArea(){
         return this.calculateSurfaceArea();
     }
     public double getVolume(){
         return this.calculateVolume();
     }
     public void setRadius(double radius2){
         myRadius = radius2;
     }

     public String toString(){
            return "Volume: " + this.getVolume() + "   Surface area " + this.getSurfaceArea();
        }
     public Sphere clone (){
            Sphere p = new Sphere();
            p.setRadius(myRadius);
            return p;
        }

}

这是我正在使用的 JUnit 测试用例

public class sphereTest {
    @Test
    public void testSphere(){
        shape3D.Sphere sphere = new shape3D.Sphere();
        sphere.setRadius(6);
        assertTrue(sphere.calculateSurfaceArea()== 452.16);
        assertTrue(sphere.calculateVolume()== 904.32);

calculateSurfaceArea() 的东西通过得很好，但音量失败了，我不确定为什么。

Answer 1

计算

myVolume = (4/3)*pi*(Math.pow(myRadius,3));

使用整数运算:4/3 的计算结果为 1。

改成

myVolume = (4.0/3)*pi*(Math.pow(myRadius,3));