C# Constructors

[mtwilson]

I am probably just be being a bit stupid but...

public MyClass( string s) : this( s, true )
public MyClass( string s, bool b )
{
    ...
}

That works fine, but what if I want to alter the string in the string in the first constructor before passing it on to the second?

public MyClass( string s)
{
   this( s + "muh", true);
}
public MyClass( string s, bool b )
{
    ...
}

That obviously doesn't work and I have tried other things so what is the solution? Unless moving the shared code into a seperate method is the only way.

 

Thanks

 

-Martin

[PlausiblyDamp]

you will have to move the code into a seperate method and call that from both constructors.

[Joe Mamma]

That obviously doesn't work and I have tried other things so what is the solution? Unless moving the shared code into a seperate method is the only way.

 

Thanks

 

-Martin

I believe so. . .

 

I am wondering if swithcing the hierarchy around might be appropriate . . .

public class MyClass
{
 string _s;
 public MyClass(string s, bool b):this(s)
 {
  // do something based on b and/or s here 
 }
 
 public MyClass(string s)
 {
// default s handling
 }
}

or a polymorphic hierarchy -

 

public class MyClass
{
 protected string _s;
 protected virtual void Manipulate(ref string s)
 {
  // default does nothing to s
 }

 public MyClass(string s, bool b)
 {
  Manipulate(s);
 _s = s;
 }
}

public class MyChildClass:MyClass
{
 protected override void Manipulate(ref string s)
 {
  s += ": Manipulated";
 }

 public MyChildClass(string s):base(s,true)
 {
 }
}

[Nerseus]

If it's as simple as appending a string, you can append it in the first example:

public MyClass( string s) : this( s + "muh", true )

 

But why would you be altering the string that the caller is passing in? Why not alter it in the "real" constructor? If it's meant to be a flag, maybe you need yet another constructor to pass in what you really want...?

 

-ner