C# Base Constructor Inheritance

Question

I'm trying to inherit from a base class but I'm getting an error that I can't figure out. This is the base class:

class Item
{
    protected string name;

    public Item(string name)
    {
        this.name = name;
    }
}

And this is the inherited class:

class ItemToBuy : Item
{
    private int lowPrice;
    private int highPrice;
    private int maxQuantity;

    public ItemToBuy(int lowPrice, int highPrice, int maxQuantity) : base(name)
    {
        this.lowPrice = lowPrice;
        this.highPrice = highPrice;
        this.maxQuantity = maxQuantity;
    }
}

The issue is this line:

public ItemToBuy(int lowPrice, int highPrice, int maxQuantity) : base(name)

where 'name' is underlined with the error message "An object reference is required for the non-static field, method or property 'Item.name'. If I replace it with a string literal the error message isn't there. What am I doing wrong with inheriting the constructor?

Answer 1

your ItemToBuy class does not have any knowledge of "name". The way you build the constructor, "name" needs to be a defined string.

Let's say that your constructor looks like this:

class ItemToBuy : Item
{
    private int lowPrice;
    private int highPrice;
    private int maxQuantity;

    public ItemToBuy(int lowPrice, int highPrice, int maxQuantity, string name) : base(name)
    {
        this.lowPrice = lowPrice;
        this.highPrice = highPrice;
        this.maxQuantity = maxQuantity;
    }
}

this will work because the name parameter is defined.

So, you either do it like that or pass a hardcoded value like you did to make it work.

Answer 2

You need to have the name in the ctor of the ItemToBuy class too

public ItemToBuy(string name ,int lowPrice, int highPrice, int maxQuantity) : base(name)

Answer 3

public ItemToBuy(int lowPrice, int highPrice, int maxQuantity) : base(name)
{
    this.lowPrice = lowPrice;
    this.highPrice = highPrice;
    this.maxQuantity = maxQuantity;
}

should be changed to:

public ItemToBuy(int lowPrice, int highPrice, int maxQuantity, string name) : base(name)
{
    this.lowPrice = lowPrice;
    this.highPrice = highPrice;
    this.maxQuantity = maxQuantity;
}

You need to specify the name parameter in the constructor, as per my code above.

Answer 4

you need to receive the name in the constructor of ItemToBuy:

public ItemToBuy(int lowPrice, int highPrice, int maxQuantity,string name) : base(name)