计算矩形的周长和面积

Question

我需要能够将矩形的长度和宽度输入控制台并计算其周长和面积.除了接受我的计算输入之外,我还有其他工作.我知道我很亲密,但似乎无法弄明白.在此先感谢您的帮助.请记住,我是一个很好的新手,所以你的答案起初可能对我没有意义.我无法计算我输入控制台的值.

package edu.purdue.cnit325_lab1;

public class Rectangle {    
    private static double length;
    private static double width;

    public Rectangle() {
        length=0.0;
        width=0.0;
    }

    public Rectangle(double l, double w) {
        length = l;
        width = w;
    }

    public double FindArea() {
        return length*width;
    }

    public double FindPerim() {
        return length*2 + width*2;
    }   
}

package edu.purdue.cnit325_lab1;

import java.util.Scanner;

public class TestRectangle {
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
            Scanner scanL = new Scanner (System.in);
            System.out.print("Please enter the length of the rectangle: ");
            double L = scanL.nextDouble();
            Scanner scanW = new Scanner (System.in);
            System.out.print("Please enter the length of the rectangle: ");
            double W = scanW.nextDouble();
            //int W = scanW.nextInt();
            double RectangleArea;
            Rectangle unitRectangle = new Rectangle(); 
            RectangleArea = unitRectangle.FindArea();
            System.out.println("The area of a unit rectangle is " + RectangleArea);

            double RectanglePermiter;
            Rectangle perimRectangle = new Rectangle();
            RectanglePermiter = perimRectangle.FindPerim();
            System.out.println("The permimiter of the unit rectangle is " + RectanglePermiter);
    }
}

Answer 1

请注意,您正在调用不带参数的Rectangle构造函数,因此将其宽度和高度设置为零,您应该使用

Rectangle unitRectangle = new Rectangle(L,W);

确实像其他答案一样,你应该使用一个Scanner实例.

另外关于编码风格:不要使用变量名称.它对于更"经验丰富"的Java开发人员来说相当混乱.:-)

Answer 2

你错过了电话parameterized constructor.

public static void main(String[] args) {
    Scanner scanL = new Scanner (System.in);
    System.out.print("Please enter the length of the rectangle: ");
    double L = scanL.nextDouble();

    System.out.print("Please enter the length of the rectangle: ");
    double W = scanL.nextDouble();


    Rectangle rectangle = new Rectangle(l,w); 
    double rectangleArea = rectangle .FindArea();
    System.out.println("The area of a unit rectangle is " + rectangleArea);

    double rectanglePermiter = rectangle.FindPerim();
    System.out.println("The permimiter of the unit rectangle is " + rectanglePermiter);
}

注意:您必须在代码中创建两个Scanner对象和两个Rectangle对象,这些对象将从上面的代码中删除.