Java中的运费计算器，得出错误的数字

Question

我是Java新手，我们正在做一个基于不同重量和距离的运费计算器。我们正在练习if-else语句，但我遇到了一个无法解决的问题。 当我计算不同的重量和距离时，我得到了错误的答案。我认为这与我的数学有关，我似乎无法让程序为距离增加下一笔费用，因为它没有使用剩余部分。请帮助我理解这一点

public class ShippingCharges {

private double weight;
private double miles;


public ShippingCharges (double w, double m)
{
    weight = w;
    miles = m;
}


public double getShippingCharges()
{
    double charges;
    if (weight <= 2.0)
    { charges = (1.10 * miles / 500);
    }
    else if ((weight > 2.0) && (weight <= 6.0))
    {
        charges = (2.20 * (miles  / 500 ));
    }
    else if ((weight > 6.0) && (weight <=10.0))
    {
        charges = (3.70 * (miles / 500 )); 
    }
    else 
    {
        charges = (4.80 * miles  / 500);
    }
    return charges;

    }
}

Answer 1

根据您所说的，我理解问题在于您没有将英里数/500的结果四舍五入，请尝试以下方法：

public double getShippingCharges()
{
    double charges;
    if (weight <= 2.0)
    { charges = (1.10 * Math.ceil(miles / 500));
    }
    else if ((weight > 2.0) && (weight <= 6.0))
    {
        charges = (2.20 * Math.ceil(miles  / 500 ));
    }
    else if ((weight > 6.0) && (weight <=10.0))
    {
        charges = (3.70 * Math.ceil(miles / 500 )); 
    }
    else 
    {
        charges = (4.80 * Math.ceil(miles  / 500));
    }
    return charges;

    }