dsiplay功能不打印输入值和计算量

Question

import java.io.*;    
import java.util.*;

class ElectricityBill { 
    int num;  
    String cname;
    int units;
    double amount = 0;

    void setData(int num, String cname, int units) { 
        Scanner in = new  Scanner(System.in);
        cname = in.nextLine();
        num = in.nextInt();
        units = in.nextInt();
    } 

    void billCalculate() { 
        if (units < 100) { 
            amount = units * 1.2;
        } else if (units >= 100 && units <= 300) { 
            amount = (100 * 1.2) + ((units - 100) * 2);
        } else if(units > 300) { 
            amount = (100 * 1.2) + (200 * 2) + ((units - 300) * 3);
        }
    }

    void show() { 
        System.out.println("Customer Number:" + num);
        System.out.println("Customer Name:" + cname);
        System.out.println("Units Consumed:" + units); 
        System.out.println("Bill to pay:" + amount);
    }  
}

public class TestClass {

     public static void main(String[] args) {
         ElectricityBill b = new ElectricityBill();
         b.setData(b.num, b.cname, b.units);
         b.billCalculate();
         b.show();
    }
}

Answer 1

看看：

    void setData(int num, String cname, int units)
    {
        Scanner in = new Scanner(System.in);
        cname = in.nextLine();
        num = in.nextInt();
        units = in.nextInt();
    }

您覆盖了方法参数。

尝试

    void setData(int num, String cname, int units)
    {
        this.num = num;
        this.cname = cname;
        this.units = units;
    }

以及

public static void main(String[] args)
{
    ElectricityBill b = new ElectricityBill();

    Scanner in = new Scanner(System.in);
    b.setData(in.nextInt(), in.nextLine(), in.nextInt());
    b.billCalculate();
    b.show();
}