iphone - String constant ... best practise? -

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i'm looking best practise of setting code-wide used string constant

option 1

extern const nsstring *cdownloadcompletenotification; (.h file)

const nsstring *cdownloadcompletenotification = @"downloadcompletenotification"; (.m file)

option 2

define knotificationdownloadcomplete @"notificationdownloadcomplete" .... (common.h)

is there benefit, 1 way or other ? ... or case of personal preference ?

personally, go former though there's not choose between them. memory usage same in both cases.

there's few things watch out in #define - e.g. if include .h file twice.

if use define , change constant's value of files might compiled old value , new - find tricky work out why notification handlers not being called! you'd have clean before building make sure changed everything. won't happen if use extern nsstring.*

hope that's helpful.

nb wouldn't declare const - compiler warning when passing postnotificationname: methods on nsnotificationcenter :(

*xcode should clever enough mark files include common.h needing rebuild if changes i've found have been wrong in past.


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