Null, Nulls, Everywhere except my constructor

Ok, here is what I want to do, it is asp.net but that really shouldn't matter as my question is more on a class constructor.

I am trying to make my page load as slim as possible. So I have an Assembly(dll) that handles a lot of things for me. One such thing is the Cookie on user preferences.

which is easy enough to do.
My constructor is like this

public UserInfo(System.Web.HttpCookie UserCookie)
{
// code that reads the cookie info and populates the class
}

Anyway I can simply new this up and pass the cookie to it all in one line Like So

UserObject = new WebControls.CoreControls.UserInfo(Request.Cookies["UserPreference"]);

Ok so here is my problem

The Cookie doesn't exist on all visitors computers, if it doesn't exist you get a null reference execption.

Ok, So I know I can do a check to see if the cookie is null, if it is I call a different constructor, if it isn;t then I call the constructor you see above. What I want to know is how I can get rid of the if statement so that if it tries to pass a null it call another constructor.

public UserInfo(null UserCookie)
{
// this doesn't work since Null is not a valid datatype.
}

I am really just trying to get to a one line constructor. and one that can handle a null.

BTW Cookies are simply a collection object. so hopefully someone has dealt with passing a null to a constructor before.

That's what overloading is for :)

Code:

---

// -- Your webform.
UserInfo myObject;
if (Request.Cookies["UserPreference"] == null) {
    myObject = new WebControls.CoreControls.UserInfo();
} else {
    myObject = new WebControls.CoreControls.UserInfo(Request.Cookies["UserPreference"]);
}

// -- Your class.
public UserInfo() {
    // Code.
}

public UserInfo(System.Web.HttpCookie UserCookie) {
    // Code.
}

---

Thanks, Axion but that is what I am currently doing I am wondering if there is anyway to do it without the if null check, like overloading the constructor to take a null type. I don't think it can but done but I am hoping so.

You'll have to use an if block anyway :shrug:

Code:

---

UserInfo myObject = new WebControls.CoreControls.UserInfo(Request.Cookies["UserPreference"]);

// -- Your class.
public UserInfo(Object UserCookie) {
    // Code.
    if (UserCookie == null) {
        // No such luck.
    } else {
        // Cookie exists.
        UserCookie = (WebControls.CoreControls.UserInfo) UserCookie;
    }
}

---

Thats what I was looking for, thanks.

I do not mind using a if block inside the class itself, I just didn't want to have to do it in the web form. Other programmers (coops and consultants) will be working with the web form so I am trying to take as much possable problems out of the equation for them and just let them reference the assembly. Cause I know one of them would be messing with the if statment then bugging me, why doesn't this work.