DaniWeb Forum Index > Software Development > C#

C# RSS

Body-less method declaration

Please support our C# advertiser: Intel Parallel Studio Home

•

Join Date: Oct 2009

Posts: 3

Reputation: serban is an unknown quantity at this point

Solved Threads: 0

serban

Offline

Newbie Poster

Body-less method declaration

33 Days Ago

Hello

I have seen the following method syntax and I am trying to understand how this works/or doesn't:

public class MyClass
{

public MyClass();

public MyClass(string param);
}

There is no implementation of the methods (constructors) and class is not declared virtual either...
Is this something new in C# 3.0 ???

Any ideas???

Thank you

•

Join Date: Feb 2009

Posts: 3,187

Reputation: sknake has much to be proud of

Solved Threads: 571

sknake

Offline

.NET Enthusiast

33 Days Ago

That doesn't compile in 3.5 and I think the error message answers your question:

Help with Code Tags

text Syntax (Toggle Plain Text)

'daniweb.MyClass.MyClass()' must declare a body because it is not marked abstract, extern, or partial
'daniweb.MyClass.MyClass(string)' must declare a body because it is not marked abstract, extern, or partial

Interfaces allow you to declare methods similarly but the method must have a return type:

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
  public interface ITest
  {
    void ITest();
  }
  public interface ITest
  {
    void ITest();
  }

I suspect you were looking at partial class definitions.

Scott Knake
Custom Software Development
Apex Software, Inc.

•

Join Date: Jun 2005

Posts: 2,039

Reputation: Rashakil Fol is just really nice

Solved Threads: 139

Rashakil Fol Rashakil Fol is offline

Offline

Super Senior Demiposter

-1

33 Days Ago

Either that or the methods were abstract.

All my posts may be redistributed under the GNU Free Documentation License.

•

Join Date: Feb 2009

Posts: 3,187

Reputation: sknake has much to be proud of

Solved Threads: 571

sknake

Offline

.NET Enthusiast

33 Days Ago

•

Originally Posted by Rashakil Fol

Either that or the methods were abstract.

You can't have abstract constructors since the child classes cannot implement constructors from an inherited class...

None of these are valid:

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
  public abstract class AbstractClass
  {
    abstract AbstractClass();
  }
  public abstract class AbstractClass2
  {
    AbstractClass2();
  }
  public class AbstractClass3
  {
    abstract AbstractClass3();
  }
  public abstract class AbstractClass
  {
    abstract AbstractClass();
  }
  public abstract class AbstractClass2
  {
    AbstractClass2();
  }
  public class AbstractClass3
  {
    abstract AbstractClass3();
  }

Scott Knake
Custom Software Development
Apex Software, Inc.

•

Join Date: Jun 2005

Posts: 2,039

Reputation: Rashakil Fol is just really nice

Solved Threads: 139

Rashakil Fol Rashakil Fol is offline

Offline

Super Senior Demiposter

33 Days Ago

•

Originally Posted by sknake

You can't have abstract constructors since the child classes cannot implement constructors from an inherited class...

Obviously I wasn't talking about his code example because the methods there were not marked abstract.

All my posts may be redistributed under the GNU Free Documentation License.

•

Join Date: Jul 2009

Posts: 886

Reputation: DdoubleD is a jewel in the rough

Solved Threads: 140

DdoubleD

Offline

Practically a Posting Shark

Note to self: why is this title field here?

32 Days Ago

•

Originally Posted by serban

Hello

I have seen the following method syntax and I am trying to understand how this works/or doesn't:

public class MyClass
{

public MyClass();

public MyClass(string param);
}

There is no implementation of the methods (constructors) and class is not declared virtual either...
Is this something new in C# 3.0 ???

Any ideas???

Thank you

Perhaps you saw some C++ code that looks like this, which in its simplest form, is very similar in appearance. In C++, this is called forward declaration. C# does not allow forward declarations.