Re: question about NSString...

[Richard Frith-Macdonald]

On 2005-06-09 01:41:11 +0100 Lloyd Dupont <lloyd@nova-mind.com> wrote:

> I have some weird problem...
>
> [NSString alloc], when called a second time, seems to return the same id 
> than 
> the 1st call.
> is it thta alloc should not be used on string? or a bug in my 
> code?

Neither .... that's normal behavior.

NSString is a class cluster ... it consists of several classes which are 
optimised for different types of string data, and when you call +alloc you 
get an instance of a general placeholder subclass.  This is replaced by an 
instance of another subclass when you initialise it.

Similar things are done by many other classes.

The general rule is that when you call any initialiser method (ie an 
instance methoid whose name begins with 'init') you must expect it to return 
a different object from the receiver and must then use the new object rather 
than the old one.