错误1类型“ Pay”已经使用相同的参数类型定义了一个名为“ ComputePay”的成员

Question

I can't seem to figure our what the issue is here. pph and with both equal to different values in the different overloads. I'm not sure what I'm doing wrong. I don't see how the values are the same.

public class Pay
{
    public double ComputePay(double h,double pph,double with)
    {
        double net = 0;

        try
        {
            double gross = h * pph;
            net = gross - with;
        }
        catch (FormatException)
        {
            Console.WriteLine("Hour's cannot be less than zero");
        }

        return net;      
    }

    public double ComputePay(double h, double pph, double with = 0.15)
    {
        double net = 0;

        try
        {
            double gross = h * pph;
            net = gross - with;
        }
        catch (FormatException)
        {
            Console.WriteLine("Hour's cannot be less than zero");
        }

        return net;
    }

    public double ComputePay(double h, double pph = 5.85, double with = 0.15)
    {
        double net = 0;

        try
        {
            double gross = h * pph;
            net = gross - with;
        }
        catch (FormatException)
        {
            Console.WriteLine("Hour's cannot be less than zero");
        }

        return net;
    }
}

Answer 1

I'm not sure what I'm doing wrong.

You've got three methods which both have three double parameters:

public double ComputePay(double h,double pph,double with)
public double ComputePay(double h, double pph, double with = 0.15)
public double ComputePay(double h, double pph = 5.85, double with = 0.15)

The fact that some of the parameters in some of the method declarations are optional is irrelevant to overloading here - you simply can't specify three methods like that. Which method would you expect to be called if the caller specifies three arguments?

Why do you want three methods anyway, given that they all do the same thing? Just get rid of the first two.

Answer 2

You cannot have two or more methods with the same signature. This means that they cannot have the same name and parameter-types. This has nothing to do with the value that will be passed to the method.

Correct could be:

public int Sum(int a, int b)
{
    return Sum(a, b, 0);
}

public int Sum(int a, int b, int c)
{
    return a + b + c;
}

Edit:

Here's an interesting MSDN-article giving guidelines about Member Overloading .

Answer 3

Your method signature (double, double, double) is the same. In this case, just delete the first two implementations. The last one will most likely already behave the way you want.

Answer 4

Your last two ComputePay (double, double, double) are the same. Having a default variable doesn't make the method different. Just use the second one and you'll be good to go.