objective-ccocoacocoa-touchxcodenslog

How to print out the method name and line number and conditionally disable NSLog?


I'm doing a presentation on debugging in Xcode and would like to get more information on using NSLog efficiently.

In particular, I have two questions:


Solution

  • Here are some useful macros around NSLog I use a lot:

    #ifdef DEBUG
    #   define DLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
    #else
    #   define DLog(...)
    #endif
    
    // ALog always displays output regardless of the DEBUG setting
    #define ALog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
    

    The DLog macro is used to only output when the DEBUG variable is set (-DDEBUG in the projects's C flags for the debug confirguration).

    ALog will always output text (like the regular NSLog).

    The output (e.g. ALog(@"Hello world") ) will look like this:

    -[LibraryController awakeFromNib] [Line 364] Hello world