simple question

[Guest]

hi,
string s = Convert.ToString(null);
why the 'Convert' class do not return "" ?

how can it work ?

 

[John Timney \(MVP\)]

null does not equal an empty string, which is what your expecting Convert to
give you.

You should initilaize string s as string.Empty or evaluate it against null
then just assign it to string.empty.

if (s == null){
s = string.Empty;
}


Regards

John Timney (MVP)

 

[Guest]

so, the 'Convert' class can't return "" ?
why should I use it ? what for ?

 

[John Timney \(MVP\)]

It converts a base data type to another base data type - if you pass null
you get null back as null doesn't have an underlying type (its a reference
type pointing to nothing), its not appropriate for converting as it converts
null to null.

The convert class is described here, pehaps you can work out what you can
use it for:
http://msdn2.microsoft.com/en-us/library/system.convert.aspx

s = Convert.ToString ((object)null);

Casting to object before the conversion should give you string.empty as a
return type.

Regards

John Timney (MVP)