Question

我没有得到答案（立方体积）

它不断返回0.0作为答案，我无法弄清楚我做错了什么。为什么volume()方法实际上不会乘以cubeSide？

import java.util.Scanner;

 class Cube{

    private double cubeSide;
    private double volumeAnswer;

    //default const
    public Cube(){
        cubeSide = 0;
    }
    //argument constructor
    public Cube(double inp){
        cubeSide = inp;
    }

    //method for volume
    public void volume(){
        volumeAnswer = cubeSide * cubeSide * cubeSide;

    }

    //returning value
    public double returnIt(){
        return volumeAnswer;
    }


}//end of class cube




public class myCubeClass{
    public static void main(String[] args){

        /*
            Cube class 
               - Two constructors (one default and the other with length argument)
               - A method called "Volume"
               - A Method called getVolume

        */

             //create new cube object 
            Cube cube1 = new Cube(3.23);  

             System.out.println("Ans: " + cube1.returnIt());



    }//end of main
}//end of class

Answer 1

永远不会调用执行计算的方法volume。最好从方法本身返回结果以避免这种类型的逻辑错误

public double getVolume() {
    return cubeSide * cubeSide * cubeSide;
}

Answer 2

volumeAnswer尚未设置为任何内容。

首先调用cube1.volume（）

初学者有返回值的问题 - JAVA

2 个答案: