(标签-java|关键词-thread)

Question

import java.util.Scanner;
public class Yuanzhui {
     public static void main(String[] args) {
       Scanner scanner=new Scanner(System.in);      
       double r=scanner.nextDouble();
       double h=scanner.nextDouble();
       Circle c = new Circle();
       c.setRadius(r);
       Cone cone=new Cone();
       cone.setBottom(c);
       cone.setHeight(h);
       System.out.printf("底面面积和周长分别为：%.2f %.2f\n",cone.getBottom().getArea(),cone.getBottom().getLength());
       System.out.printf("体积为：%.2f\n",cone.getVolume());      
       scanner.close();
   }
}

class Circle{
    private double radius;
    
    public void setRadius(double radius) {
        this.radius=radius;
    }
    public double getRadius() {
        return this.radius;
    }
    
    public double getArea() {
        return this.radius*this.radius*Math.PI;
    }
    public double getLength() {
        return 2*this.radius*Math.PI;
    }
}

class Cone extends Circle{
    
    private double height;
    private double bottom;
    
    public Cone() {
        this.bottom=super.getArea();
        
    }
    
    public void setBottom(Circle circle) {
        this.bottom=circle.getArea();
        
        super.getLength();
        super.getArea();
    }
    
    public double getBottom() {
        return this.bottom;
    }
    public double getHeight() {
        return this.height;
    }
    
    public void setHeight(double height) {
        this.height=height;
    }
    public double getVolume() {
        return this.height*this.bottom/3.0;
    }
}

以上代码存在编译问题：
Exception in thread "main" java,lang.Error: Unresolved compilation problems:
Cannot invoke getArea() on the primitive type double
Cannot invoke getLength() on the primitive type double
The method printf(String, Object[]) in the type PrintStream is not applicable for the
arguments (String, double)
希望知道该如何解决，谢谢。

Answer 1

以下内容由CHATGPT及阿里嘎多学长共同生成、有用望采纳：

---

在你的代码中，有几个错误需要修复。首先，Cone 类的构造函数和 setBottom 方法中尝试对 double 类型的 height 和 bottom 调用 getArea() 和 getLength()，这是不正确的，因为这些方法是 Circle 类的方法，应该对 Circle 对象调用。其次，printf 方法的参数格式有误。以下是修复后的代码：

import java.util.Scanner;

public class Yuanzhui {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double r = scanner.nextDouble();
        double h = scanner.nextDouble();
        Circle c = new Circle();
        c.setRadius(r);
        Cone cone = new Cone();
        cone.setBottom(c);
        cone.setHeight(h);
        System.out.printf("底面面积和周长分别为：%.2f %.2f\n", c.getArea(), c.getLength());
        System.out.printf("体积为：%.2f\n", cone.getVolume());
        scanner.close();
    }
}

class Circle {
    private double radius;

    public void setRadius(double radius) {
        this.radius = radius;
    }

    public double getRadius() {
        return this.radius;
    }

    public double getArea() {
        return this.radius * this.radius * Math.PI;
    }

    public double getLength() {
        return 2 * this.radius * Math.PI;
    }
}

class Cone extends Circle {

    private double height;
    private double bottomArea; // 修改了变量名，从 bottom 改为 bottomArea

    public Cone() {
        this.bottomArea = super.getArea(); // 使用 super.getArea() 而不是 this.bottom.getArea()
    }

    public void setBottom(Circle circle) {
        this.bottomArea = circle.getArea();
    }

    public double getBottomArea() { // 更改了方法名，从 getBottom 改为 getBottomArea
        return this.bottomArea;
    }

    public double getHeight() {
        return this.height;
    }

    public void setHeight(double height) {
        this.height = height;
    }

    public double getVolume() {
        return this.height * this.bottomArea / 3.0;
    }
}

现在代码应该可以正确编译并运行了。注意，我修改了 Cone 类中的 bottom 变量名和相关方法，以避免与圆的面积混淆。同时，修复了 printf 方法的参数问题。