C# creating a non-nullable string. Is it possible? Somehow?

Question

So you can't inherit string. You can't make a non-nullable string. But I want to do this. I want a class, let's call it nString that returns a default value when it would otherwise be null. I have JSON objects that might have who knows how many null strings, or even null objects. I want to create structs that have strings that will never return null.

public struct Struct
{
    public nString value;
    public nString value2;
}

I suppose I could do something like this:

public struct Struct
{
    public string val { get { return val ?? "N/A"; } set { val = value; } }
    public string val2 { get { return val2 ?? "N/A"; } set { val2 = value; } };
}

But that's so much more work. Is there any way to do this?

Answer 1

You could of course have the following nString struct:

public struct nString
{
    public nString(string value)
        : this()
    {
        Value = value ?? "N/A";
    }

    public string Value
    {
        get;
        private set;
    }

    public static implicit operator nString(string value)
    {
        return new nString(value);
    }

    public static implicit operator string(nString value)
    {
        return value.Value;
    }
}

...

public nString val 
{ 
    get;
    set;
}

obj.val = null;
string x = obj.val; // <-- x will become "N/A";

This would allow casting from and to string. Under the hood it performs the same cast as your example, you just don't have to type it out for every property. I do wonder what this does to maintainability for your application though.