关于构造函数中不同数据类型的初学者问题

Question

我是编码新手，目前正在使用 Java 进行 OOP 工作。我的老师让我们创建一个矩形类，而不是仅仅导入内置类。不管怎样，我们要创建以整数和双精度作为参数的构造函数。我的问题是，如果数据类型不同，有两个构造函数，我是否需要为每种类型使用单独的 getter / setter？这是我可以使用通用数据类型的时候吗？我已将我创建的内容包含在下面。谢谢。

public class Rectangle {
    
    private int height;
    private int width;
    private double doubleHeight;
    private double doubleWidth;
    
    public Rectangle() {
        height = 0;
        width = 0;
    }
    
    public Rectangle(int h, int w) {
        height = h;
        width = w;
        System.out.println("A Rectangle has been created using integer dimensions.");
    }
    
    public Rectangle(double h, double w) {
        doubleHeight = h;
        doubleWidth= w;
        System.out.println("A Rectangle has been created using double dimensions.");
    }
    
    public int getIntHeight() {
        return height;
    }
    
    public double getDoubleHeight() {
        return doubleHeight;
    }
    
    public int setIntHeight(int h) {
        height = h;
    }
    
    public double setDoubleHeight(double h) {
        doubleHeight = h;
    }
    
    public int getIntArea() {
        return width * height;
    }
    
    public double getDoubleArea() {
        return doubleWidth * doubleHeight;
    }
    
    public int getIntPerimeter() {
        return width*2 + height*2;
    }
    
    public double getDoublePerimeter() {
        return doubleWidth*2 + doubleHeight*2;
    }
    
    public String toString() {
        if (this.getIntHeight() >= 1) {
            return "Height: " + height + ", Width: " + width;
        }
        else {
            return "Height: " + doubleHeight + ", Width: " + doubleWidth;
        }
    }
}

Answer 1

是的，如果您希望两种类型都可访问，则需要不同的 getter。由于参数类型不同，您的 setter 可以具有相同的名称。如有必要，您可以将这些 getter/setter 强制转换为构造函数中使用的类型。例如：

public class Rectangle {

    private int height;
    private int width;
    private double doubleHeight;
    private double doubleWidth;

    public Rectangle() {
        this.height = 0;
        this.width = 0;
    }

    public Rectangle(int h, int w) {
        this.height = h;
        this.width = w;
        System.out.println("A Rectangle has been created using integer dimensions.");
    }

    public Rectangle(double h, double w) {
        this.doubleHeight = h;
        this.doubleWidth = w;
        System.out.println("A Rectangle has been created using double dimensions.");
    }

    public int getIntHeight() {
        if (this.height > 0)
            return this.height;
        else
            return (int) getDoubleHeight();
    }

    public double getDoubleHeight() {
        if (this.doubleHeight > 0)
            return this.doubleHeight;
        else
            return (double) getIntHeight();
    }

    public void setHeight(int h) {
        if (this.height > 0)
            this.height = h;
        else
            setHeight((double) h);
    }

    public void setHeight(double h) {
        if (this.doubleHeight > 0)
            this.doubleHeight = h;
        else
            setHeight((int) h);
    }

    public int getIntArea() {
        if (this.height > 0)
            return this.width * this.height;
        else
            return (int) getDoubleArea();
    }

    public double getDoubleArea() {
        if (this.doubleWidth > 0)
            return this.doubleWidth * this.doubleHeight;
        else
            return (double) getIntArea();
    }

    public int getIntPerimeter() {
        if (this.height > 0)
            return this.width * 2 + this.height * 2;
        else
            return (int) getDoublePerimeter();
    }

    public double getDoublePerimeter() {
        if (this.doubleHeight > 0)
            return this.doubleWidth * 2 + this.doubleHeight * 2;
        else
            return (double) getIntPerimeter();
    }

    public String toString() {
        if (this.height >= 1) {
            return "Height: " + this.height + ", Width: " + this.width;
        } else {
            return "Height: " + this.doubleHeight + ", Width: " + this.doubleWidth;
        }
    }
}

Answer 2

您应该将高度和宽度存储为双精度数（因为双精度数比 int 宽，即 int 可以放入 double 但 double 不能放入 int 中），然后让带有 double 和 int 参数的构造函数简单地设置 double 高度和宽度的值。

无需使用通用数据类型。

它应该是这样的：

公共类矩形{

private double height;
private double width;

public Rectangle() {
    height = 0;
    width = 0;
}

public Rectangle(int h, int w) {
    height = h;
    width = w;
    System.out.println("A Rectangle has been created using integer dimensions.");
}

public Rectangle(double h, double w) {
    height = h;
    width = w;
    System.out.println("A Rectangle has been created using double dimensions.");
}

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

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

public double getWidth() {
    return this.width;
}

public void setWidth(double w) {
    this.width = w;
}

public double getArea() {
    return width * height;
}

public double getPerimeter() {
    return width * 2 + height * 2;
}

public String toString() {
    return "Height: " + height + ", Width: " + width;
}

}