Check device OS version

Alertnative 1 :
NSArray *vComp = [[UIDevice currentDevice].systemVersion componentsSeparatedByString:@"."];

           
if ([[vComp objectAtIndex:0] intValue] >= 7) {

      // OS 7 code here

}

Alertnative 2 :
NSString *reqSysVer = @"7.0";
NSString *currSysVer = [[UIDevice currentDevice] systemVersion];

    

if ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending) {

     // OS 7 code here

}