java - 创建自定义类! java

Question

我是 Java 的新手，正在完成一项作业。我应该创建自己的类“Cylinder”并从中调用方法以便能够打印出半径和高度，然后更改它并再次打印出来。我得到它来打印 cylinder1 和 cylinder1.setRadius/setHeight 的设置值..我的问题是我必须让它打印像 Cylinder Radius: 和 Height:...但是当它打印时我得到的是 3.04.0或设置为...我花了很长时间试图解决这个问题，请提供任何帮助!

public class Funtimes{

  public static void main(String[] args){
    Cylinder cylinder1= new Cylinder(1,2);
    System.out.println(cylinder1);

    cylinder1.setRadius(3);
    cylinder1.setHeight(4);
    System.out.println(cylinder1);
  }}

class Cylinder
{
  private double radius, height, area, volume;

  public Cylinder(double height, double radius){
    this.radius = radius;
    this.height=height;
  }

  public double getRadius() {
    return radius;
  }

  public double getHeight() {
    return height;
  }

  public double getArea() {
    double area = (2 * Math.PI * radius * height) + (2 * Math.PI * Math.pow(radius, 2));
    return area;
  }

  public void setRadius(double r) {
    radius = r;
  }

  public void setHeight(double h) {
    height = h;
  }

  public double calcVolume() {
    double volume = Math.PI * Math.pow(radius, 2) * height;
    return volume;
  }

  public String toString (){
    StringBuilder StBuild = new StringBuilder();
    StBuild.append(radius).append(height);
    return StBuild.toString();        
  }

  public static void main(String[] args) {
    Cylinder cylinder1 = new Cylinder(5, 5);
    System.out.println(cylinder1);
  }

}

Answer 1

修改你的toString()

public String toString () {
    return String.format("Radius: %s Height: %s", radius, height);       
}