#define

I always use following #define in my .pch

    //Debug Log instead of NSLog

#ifdef DEBUG
#define DLog( s, ... ) NSLog( @"<%@:(%d)> %@", [[NSString stringWithUTF8String:__FILE__] lastPathComponent], __LINE__, [NSString stringWithFormat:(s), ##__VA_ARGS__] )
#else
#define DLog( s, ... )
#endif

//Directory

#define DocumentsDirectory [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]

#define LibraryDirectory [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) objectAtIndex:0]

#define DocumentsSubDirectory(dir) [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingString:dir]

#define LibrarySubDirectory(dir) [[NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,  NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingString:dir]

#define CacheDirectory [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0]


//NSString trim

#define trim( object ) [object stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet] ]