Constructors calling one another ...

[Mark]

A class can have more than one constructor, but can't one constructor call
another? It appears that the code below bombs and the error message claims
.... "denotes a 'class' which is not valid in the given context".

Thanks in advance! - Mark

public class cWhatever
{
public cWhatever(String str1)
{
whatever(str1, string.Empty);
}
public cWhatever(String str1, String str2)
{
//Do something
}
}

 

[Michael Culley]

The other alternative is to put the code into a seperate function and call that from both constructors. That was you can execute the
initialization code wherever you like in the constructor.

 

[Keith Patrick]

Just my $.02, but I prefer the former method. Reduces the paths of code to
1 and means less changes to make if all paths ultimately lead to a single
ctor.

The other alternative is to put the code into a seperate function and call

that from both constructors. That was you can execute the

 

[Jeff Louie]

Mark.... You can chain constructors or use static factory methods.

http://www.geocities.com/jeff_louie/OOP/oop4.htm

Regards,
Jeff

 

[William Stacey]

However if you use a private method, then the paths lead there as well
(assuming your not doing anything else in the constructor.) Even if you
use "this", you can still have other code in the constructors that gets
executed after the "this" so there is no gaurentee of only one path, only
that some common code will get excecuted. So it's probably about the same
either way? Not advocating either way, just poking for knowledge myself.

--
William Stacey, DNS MVP

Just my $.02, but I prefer the former method. Reduces the paths of code to
1 and means less changes to make if all paths ultimately lead to a single
ctor.

The other alternative is to put the code into a seperate function and

call
that from both constructors. That was you can execute the

 

[Michael Culley]

But if you want the initialisation code run at the end of the constructor you've got no choice.

--
Michael Culley

Just my $.02, but I prefer the former method. Reduces the paths of code to
1 and means less changes to make if all paths ultimately lead to a single
ctor.

The other alternative is to put the code into a seperate function and call

that from both constructors. That was you can execute the

 

[Keith Patrick]

Which is why all of my "other" ctors have no code in them; they are merely
overloads in lieu of default parameter support in the language.

However if you use a private method, then the paths lead there as well
(assuming your not doing anything else in the constructor.) Even if you
use "this", you can still have other code in the constructors that gets
executed after the "this" so there is no gaurentee of only one path, only
that some common code will get excecuted. So it's probably about the same
either way? Not advocating either way, just poking for knowledge myself.

 

[Jon Skeet]

A class can have more than one constructor, but can't one constructor call
another? It appears that the code below bombs and the error message claims
... "denotes a 'class' which is not valid in the given context".

<snip>

In addition to the other responses, you might want to read
http://www.pobox.com/~skeet/csharp/constructors.html

 

[William Stacey]

That is nice if you can do it. Sometimes that is not possible or you have
to make the one ctor overly complex to handle all the different parms.

 

[William Stacey]

Thanks Jon. Always good info.

 

[Scott C. Wagner]

You cannot initialize readonly class members in a private function.
Those can only be assigned to in a ctor. Therefore, in some cases, it
is important that you redirect to another ctor instead of a private
function.

Scott Wagner
Seisint, Inc.

 

[Keith Patrick]

Why? If all your ctors call a master one, and the only copy of the init
code is there, it will run at the end of the construction process.

But if you want the initialisation code run at the end of the constructor you've got no choice.