c# constructors issues

Question

User410067686 posted

private string _brand = "";

private string _model = "";

Public Class (string brand)

{

     _brand = brand;
}

Public Class (string model)

{

     _model = model
}

There is an error stating the call is ambiguous, I need two constructors but only one parameter that is different.

Answer 1

User-1360095595 posted

These method/constructors are identical. They take a string as a parameter. That's the cause if the error. 

Why not create just one constructor that takes two string parameters. 

Answer 2

User410067686 posted

But I just need a single parameter

Answer 3

User-1360095595 posted

Pass empty string for the other. 

Once again, you can't have two constructors that take the same number/type of parameter. 

Answer 4

User410067686 posted

what u mean for this, can give illustration? Thanks :)

Answer 5

User281315223 posted

The compiler doesn't really work that way, it sees that both constructors for your particular class accept a single string (it doesn't care what the string looks like) so it assumes that the signatures of each method are identical and thus ambiguous.

You have a few options as detailed below.

Create an Additional Constructor

If you create an additional constructor, you could always have the option of simply passing in either a null or empty string for the parameter you aren't concerned about at the time :

private string _brand = "";
private string _model = "";

public Class(string brand)
{
     _brand = brand;
}

public Class(string brand, string model)
{
     _brand = brand;
     _model = model;
}

This way if you only had one value to populate it with (either brand or model), you could just pass in one or the other :

Class x = new Class("Your Brand", null);

Using an Empty Constructor

If you create an empty constructor, it would allow you to use the anonymous syntax as seen below to set each of your individual properties. You would likely need to make a publicly accessible interface to use this approach however :

private string _brand = "";
private string _model = "";

public string Brand { get { return _brand; } set { _brand = value; } }
public string Model { get { return _model; } set { _model = value; } }

public Class()
{

}

which you could use through :

Class x = new Class(){ Brand = "Your Brand", Model = null };

 

Answer 6

User410067686 posted

public Class(string brand, string model)
{
     _brand = brand;
     _model = model;
}

For example , I just need model, how do I create a null for this

Answer 7

User281315223 posted

public Class(string brand, string model)
{
     _brand = brand;
     _model = model;
}

For example , I just need model, how do I create a null for this

You would just need to use :

Class x = new Class(null,"Your Model");

or :

Class x = new Class("","Your Model");

Answer 8

User410067686 posted

public Class(null, string model)
{
     null = null
     _model = model;
}

Can I do in this way?