Why can't a string be default-constructed?

  • Thread starter Thread starter Andreas Huber
  • Start date Start date
A

Andreas Huber

Hi there

Can anyone imagine a reason why string does not have a default ctor?

Agreed, that might be necessary only very rarely in .NET 1.1 code.
However, in conjunction with .NET 2.0 and generics it is just plain
annoying. Example:

class Param< T > where T : new()
{
public Param()
{
val = new T(); // here
}

// Other members

private T val;
}

Of course I would want to instantiate the Param template with all kinds
of types, e.g. double, int, and - you guessed it - string.

Thanks & Regards,
 
Can anyone imagine a reason why string does not have a default ctor?
Click to expand...

What good would such a string do you, and what would its value be
(String.Empty?)

Can't you use default(T) for the initialization instead?



Mattias
 
Mattias said:
What good would such a string do you,
Click to expand...

Well, no matter with what type I instantiate the generic class, I want
the T member to be default constructed. Assigning null to a
reference-type is definitely not an option.
While I agree that some types cannot be meaningfully default
constructed, I don't think System.String is one of them.
and what would its value be
(String.Empty?)
Click to expand...

"" (String.Empty == true), what else?
Can't you use default(T) for the initialization instead?
Click to expand...

No, that would assign null.

Regards,
 
You are the second guy today in this newsgroup who is asking for a
parameterless constructor for System.String :)
 
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