Question

I’m getting ‘Order’ does not contain a constructor that takes 0 arguments. So based on that error, I know it’s in my public class Order. What am I overlooking? Thanks!

public class Order
{
    public int QuantityOrdered { get; set; }
    public double TotalPrice;
    public const double PRICEEACH = 19.95;

    virtual public double totalPrice
    {
        set
        {
            TotalPrice = QuantityOrdered * PRICEEACH;
        }
    }
}

public class ShippedOrder : Order
{
    public const double SHIPPINGFEE = 4.00; 
    public override double totalPrice
    {
        set
        {
            totalPrice = base.TotalPrice + SHIPPINGFEE;
        }
    }
}

Answer 1

There has to be a constructor in the Order class you haven’t listed in the code you provided.

When you do not define any constructors for a class, you’re given an implicit parameterless constructor by the compiler.

However, when you add a constructor that takes a parameter, ex. public Order(string someString) {}, you lose this implicit constructor.

What you need to do is one of the following:

1. Add an explicit parameterless constructor, ex. public Order() {}

2. Update the code that’s instantiating the Order object to pass the parameter it’s looking for, ex. new Order(someString)

3. Remove the constructor(s) from Order that expect parameters.