iOS常用判断的宏定义：系统版本号，屏幕宽高，设备型号, 自定义NSLog等

／／设备型号

#define IS_IPAD     [[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad

#define IS_IPHONE   [[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone

#define IS_IPHONE_4 (fabs((double)[[UIScreen mainScreen] bounds].size.height - (double )480) < DBL_EPSILON )

#define IS_IPHONE_5 (fabs((double)[[UIScreen mainScreen] bounds].size.height - (double )568) < DBL_EPSILON )

#define IS_IPHONE_6 (fabs((double)[[UIScreen mainScreen] bounds].size.height - (double )667) < DBL_EPSILON )

#define IS_IPHONE_6_PLUS (fabs((double)[[UIScreen mainScreen] bounds].size.height - (double )960) < DBL_EPSILON )

／／系统版本

#define IS_IOS_VERSION   floorf([[UIDevice currentDevice].systemVersion floatValue]

#define IS_IOS_5    floorf([[UIDevice currentDevice].systemVersion floatValue]) ==5.0 ?1 : 0

#define IS_IOS_6    floorf([[UIDevice currentDevice].systemVersion floatValue]) ==6.0 ?1 : 0

#define IS_IOS_7    floorf([[UIDevice currentDevice].systemVersion floatValue]) ==7.0 ?1 : 0

#define IS_IOS_8    floorf([[UIDevice currentDevice].systemVersion floatValue]) ==8.0 ?1 : 0

#define IS_IOS_9    floorf([[UIDevice currentDevice].systemVersion floatValue]) ==9.0 ?1 : 0

／／物理屏幕尺寸

#define IH_DEVICE_HEIGHT    [[UIScreen mainScreen] bounds].size.height

#define IH_DEVICE_WIDTH     [[UIScreen mainScreen] bounds].size.width

／／自定义的NSLog

#ifdef DEBUG

#define XSLog(FORMAT, ...) fprintf(stderr,"%s:%d\t%s\n",[[[NSString stringWithUTF8String:__FILE__] lastPathComponent] UTF8String], __LINE__, [[NSString stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String]);

#define YYLog(FORMAT, ...) fprintf(stderr,"%s:%d\t%s\n",[[[NSString stringWithUTF8String:__FILE__] lastPathComponent] UTF8String], __LINE__, [[NSString stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String]);

#else

#define XSLog(FORMAT, ...) nil;

#define YYLog(FORMAT, ...) nil;

#endif