Get the instance name of the object no the object type name in C# 4.0

Question

Assume this type:

public class Car { }

And I create an instance of that:

Car myCar = new Car();

Target target = new Target();
target.Model = myCar;

And this is another Type:

public class Target {

   public object Model { get; set; }

   string GetName(){

     //Use Model and return myCar in this Example
   }

}

As I showed in code the GetName method must use an object type (Model) and returned the name of instance that is myCar in this example? what is your suggestion is there any way to do this?

Update How about this:

public class Car {

  public string Title { get; set; }

}

And I pass to target: target.Model = Car.Title

And GetName() method returned Title ?

Variable name doesn't make and should not make any sense in business logic — zerkms, Apr 18 '12 at 08:14
Why is `Model` just an object instead of a `Car` (or a subclass of it)? — Tim Schmelter, Apr 18 '12 at 08:17
It's unclear what the point of `Target` is. But you'd want to do `target.Model = myCar` and then probably later cast it back to a `Car` and access the `Title` property. So something like `Car car = target.Model as Car; if (car != null) { // Do something with your car object }`. — Adrian Thompson Phillips, Apr 18 '12 at 08:43

score 5 · Answer 1 · answered Apr 18 '12 at 08:16

5

Objects do not have a name, unless they explicitly have a way to store their name. myCar is a local variable - the object itself (the Car) does not know that you are referring to it by the name myCar. To illustrate:

Car myCar = new Car();
Car car2 = myCar;
Car car3 = myCar;

Now all three variables refer to the same Car.

If you want cars to have names, you could do

public class Car 
{
    public string Name { get; set; }
}

and then assign and read whatever name you want it to have.

answered Apr 18 '12 at 08:16

AakashM

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Well, you could always return a list of names... just kidding ;-) +1. – Christian.K Apr 18 '12 at 08:20
I Update Question what you think now? – Saeid Apr 18 '12 at 08:20

score 3 · Accepted Answer · answered Apr 18 '12 at 08:16

No, this is not possible. Why? Because myCar is only a name for your Car instance inside the scope which you set up the variable for. What gets saved to target.Model is a reference to the Car instance. So, after your sample code, both myCar and target.Model reference the same instance of Car, just with different names. The names themselves are rather unimportant to the execution of the program, it's just a trick we use to make talking about instances easier.

I Update Question what you think now? – Saeid Apr 18 '12 at 08:20 — Saeid, Apr 18 '12 at 08:20

score 1 · Answer 3 · answered Apr 18 '12 at 08:16

There is no such thing as "name of the instance". What you're saying about is the name of the specific reference to the object; there could be many references to the same object, all with different names. Also, linking code and data (i.e. relying on the variable name) is a bad practice.

If you want Car to have some name, then name it explicitly:

public class Car {
    public string Name { get; set; }
} 

Car myCar = new Car { Name = "myCar" };

Get the instance name of the object no the object type name in C# 4.0

3 Answers3

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