Using New but not set to an instance? 1

[JoeAtWork]

I’m studying an example of MVP code, the following looks wrong to me (although it works fine):

      PuzzleForm view = new PuzzleForm();
      IPuzzleModel model = new PuzzleModel(loadImageModel, imageCutter);
      new PuzzlePresenter(model, view);

On the third line, why isn’t it creating an instance of PuzzlePresenter? I have not seen this syntax before. I would expect something like:

PuzzlePresenter myPresenter = new PuzzlePresenter(model, view);

Can you “new” something but it’s not set to anything? Coming from a VB6 background, it just feels wrong to me.

So is it that there is an instance created, but I just don't have a handle to it via a variable?

Is the scope of this instance within the subroutine where it is created?

 

[JurkMonkey]

Put a breakpoint in on the 3rd line and see what item is null. It may be something inside the creation of one of your objects. Take a look in the constructor of the PuzzlePresenter class.

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[JoeAtWork]

I'm sorry, rereading my question I see it is completely misleading.

There is nothing wrong with the code, it works just fine. I am just confused about the syntax, i.e. using the "New" keyword but not setting it to a variable.

 

[JurkMonkey]

You can do that and use the class in that single line for the scope of that line.

For example:

string type = new MyObject().GetType().ToString();

Same as you could do:

Console.WriteLine(new MyObject().GetType().ToString());

Typically you would want to assign it to a variable but you don't have to.

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[JoeAtWork]

Thanks, I won't worry about it further.