Constructor initializers

[Magne Ryholt]

Assume a class DerivedClass has two constructors:

DerivedClass(int a)
{
// some code
}

DerivedClass(int a, int b) : base(a, b)
{
}
As you can see, I want the second constructor to execute code in a base
class constructor, however I also want the second constructor to execute the
code in the first constructor (in the DerivedClass),
denoted as // some code.

I can only see 2 alternatives:

Alternative 1: copy all the code in the first constructor (// some code), so
that the second constructor looks like:
DerivedClass(int a, int b) : BaseClass(a, b)
{
// some code
}
This approach may lead to maintenance problems.

Alternative 2: factorize the code to another (instance) method (should be
private) and call it from both constructors.
This alternative works.

Anyone knows a better approach ? I am looking for something like:
DerivedClass(int a, int b) : base(a, b) , this(a) (executing both a base
class constructor and a "sibling" constructor)

[Marina]

The other option is to move //some code into the second constructor, and
have the first one call the second, with a default value for 'b'.

"Magne Ryholt" <ma**********@bluezone.no> wrote in message
news:OF**************@tk2msftngp13.phx.gbl...

Assume a class DerivedClass has two constructors:

DerivedClass(int a)
{
// some code
}

DerivedClass(int a, int b) : base(a, b)
{
}
As you can see, I want the second constructor to execute code in a base
class constructor, however I also want the second constructor to execute the code in the first constructor (in the DerivedClass),
denoted as // some code.

I can only see 2 alternatives:

Alternative 1: copy all the code in the first constructor (// some code), so that the second constructor looks like:
DerivedClass(int a, int b) : BaseClass(a, b)
{
// some code
}
This approach may lead to maintenance problems.

Alternative 2: factorize the code to another (instance) method (should be
private) and call it from both constructors.
This alternative works.

Anyone knows a better approach ? I am looking for something like:
DerivedClass(int a, int b) : base(a, b) , this(a) (executing both a base
class constructor and a "sibling" constructor)

[Nicholas Paldino [.NET/C# MVP]]

Magne,

In this case, you should just have the overload with one parameter call
the overload with two parameters, like so:

DerivedClass(int a) : this(a, 0)
{}

DerivedClass(int a, int b) : base(a, b)
{}

Is there a value that can be used for b which is outside what is
expected? If so, use that. I use zero only as an example here.

Hope this helps.

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com
"Magne Ryholt" <ma**********@bluezone.no> wrote in message
news:OF**************@tk2msftngp13.phx.gbl...

Assume a class DerivedClass has two constructors:

DerivedClass(int a)
{
// some code
}

DerivedClass(int a, int b) : base(a, b)
{
}
As you can see, I want the second constructor to execute code in a base
class constructor, however I also want the second constructor to execute
the code in the first constructor (in the DerivedClass),
denoted as // some code.

I can only see 2 alternatives:

Alternative 1: copy all the code in the first constructor (// some code),
so that the second constructor looks like:
DerivedClass(int a, int b) : BaseClass(a, b)
{
// some code
}
This approach may lead to maintenance problems.

Alternative 2: factorize the code to another (instance) method (should be
private) and call it from both constructors.
This alternative works.

Anyone knows a better approach ? I am looking for something like:
DerivedClass(int a, int b) : base(a, b) , this(a) (executing both a base
class constructor and a "sibling" constructor)

[Magne Ryholt]

Thank you,
sure I could, however I forgot to say that the first constructor (in
DerivedClass) looks like: DerivedClass(int a) : base(a)
Sorry :)

"Marina" <so*****@nospam.com> wrote in message
news:%2****************@TK2MSFTNGP15.phx.gbl...

The other option is to move //some code into the second constructor, and
have the first one call the second, with a default value for 'b'.

"Magne Ryholt" <ma**********@bluezone.no> wrote in message
news:OF**************@tk2msftngp13.phx.gbl...

Assume a class DerivedClass has two constructors:

DerivedClass(int a)
{
// some code
}

DerivedClass(int a, int b) : base(a, b)
{
}
As you can see, I want the second constructor to execute code in a base
class constructor, however I also want the second constructor to execute

the

code in the first constructor (in the DerivedClass),
denoted as // some code.

I can only see 2 alternatives:

Alternative 1: copy all the code in the first constructor (// some code),

so

that the second constructor looks like:
DerivedClass(int a, int b) : BaseClass(a, b)
{
// some code
}
This approach may lead to maintenance problems.

Alternative 2: factorize the code to another (instance) method (should be
private) and call it from both constructors.
This alternative works.

Anyone knows a better approach ? I am looking for something like:
DerivedClass(int a, int b) : base(a, b) , this(a) (executing both a base
class constructor and a "sibling" constructor)