Question

So the compiler will not allow me to overrload the == and != operators of my class. Here is what the class looks like:

public class Item
{
    public string _name;
    public double _weight;
    public decimal _wholesalePrice;
    public int _quantity;

    public Item(string name, double weight, decimal wholesalePrice, int quantity)
    {
        _name = name;
        _weight = weight;
        _wholesalePrice = wholesalePrice;
        _quantity = quantity;
    }

    public static override bool operator ==(Item left, Item right)
    {
        if (left._name == right._name)
        {
            return true;
        }
        return false;
    }

    public static override bool operator !=(Item left,Item right)
    {
        return !(left == right);
    }
}

The compiler keeps telling me “The modifier ‘override’ is not valid for this item. At first I thought I might not have declared a base method as virtual, but my class does is not derived. Any ideas what’s happening?

Answer 1

You cannot declare an override unless you have derived the class from a parent class. You also cannot declare override on a static method. Have you tried removing override all together? That seems to work for me…

public class Item
{
    public string _name;
    public double _weight;
    public decimal _wholesalePrice;
    public int _quantity;

    public Item(string name, double weight, decimal wholesalePrice, int quantity)
    {
        _name = name;
        _weight = weight;
        _wholesalePrice = wholesalePrice;
        _quantity = quantity;
    }

    public static bool operator ==(Item left, Item right)
    {
        if (left._name == right._name)
        {
            return true;
        }
        return false;
    }

    public static bool operator !=(Item left, Item right)
    {
        return !(left == right);
    }
}

As a side note, if you override the == and != operators, it’s also good practice to override the GetHashCode and Equals methods.