Comparing version numbers

Question

Some time ago, I read that comparing version numbers can be done using the following code snippet:

NSString *vesrion_1 = @\"1.2.1\";
NSString *version_2 = @\         


        

Answer 1

I like Mike's (less code) answer but this should also work even if there is a question about the compare option NSNumericSearch works.

- (NSComparisonResult)compareVersion:(NSString *)versionA to:(NSString *)versionB
{
   NSArray *versionAComp = [versionA componentsSeparatedByString:@"."];
   NSArray *versionBComp = [versionB componentsSeparatedByString:@"."];

   __block NSComparisonResult result = NSOrderedSame;

   [versionAComp enumerateObjectsUsingBlock:
   ^(NSString *obj, NSUInteger idx, BOOL *stop)
   {
        // handle abbreviated versions.
        if (idx > versionBComp.count -1)
        {
            *stop = YES;
            return;
        }

        NSInteger verAInt = [versionAComp[idx] integerValue];
        NSInteger verBInt = [versionBComp[idx] integerValue];

        if (verAInt != verBInt)
        {
            if (verAInt < verBInt)
                result = NSOrderedAscending;
            else
                result = NSOrderedDescending;

            *stop = YES;
            return;
        }
    }];
   return result; 
}