Overloaded constructors in C# similar to Delphi (with multiple names)

Question

I am trying to port some code from Delphi to C# and I have found a construction which I cannot implement in a reasonable manner, while complying with .NET Framework design guidelines (which I address at the end of my question). Obviously C#, Java, C++ (and many other languages) provide meanings of method/constructor overloading, but Delphi constructors can additionally have multiple names. This way it's possible to write code which directly represents the intent: ``` var Data, ParI, ParD, Locl: TDataElement; begin Data := TDataElement.Create('Element'); ParI := TDataElement.CreateParam('IntElement', 22); ParD := TDataElement.CreateParam('DblElement', 3.14); Locl := TDataElement.CreateLocal('LocalElement'); // ... use the above objects ... end; ``` Simplified code below: ``` unit DataManager; interface TDataElement = class FName: string; FPersistent: Boolean; public constructor Create(AName: string); constructor CreateParam(AName: string; DefaultInt: Integer); overload; constructor Cre…

Accepted Answer

For starters, I would replace your nested "ElementKind" `class` with an `enum`:

```
public enum ElementKind
{
    RegularElement,
    IntParamElement,
    DoubleParamElement,
    LocalElement
}
```

In addition, I don't think your Delphi code needs to be mapped to a constructor. You would probably be better off using static factory methods that return a `DataElement`. For example:

```
public static DataElement Create(string name)
{
    return new DataElement(ElementKind.Regular, name);
}

public static DataElement CreateParam(string name, int defaultInt);
{
    return new DataElement(ElementKind.IntParam, name);
    // ... use defaultInt ... 
}

// similar to above
public static DataElement CreateParam(string name, double defaultDouble); 
public static DataElement CreateLocal(string name);
```

Since you're using the factory functions to create your DataElement objects, you should make the constructors private.

You would then update your Run() function to use these as follows:

```
public void Run() 
{ 
    DataElement data = DataElement.Create("Element");
    DataElement parI = DataElement.CreateParam("IntElement", 22);
    DataElement parD = DataElement.CreateParam("DblElement", 3.14); 
    DataElement locl = DataElement.CreateLocal("LocalElement"); 
} 
```

Update: I included the suggested changes to your `Run()` function and corrected the basic `Create()` factory method (I believe it's supposed to return a "Regular" `DataElement`).

Overloaded constructors in C# similar to Delphi (with multiple names)

Solution

Problem