Check if iOS Update is available using objective-c?

Question

How can I compare installed iOS version with the latest iOS version programatically using objective-c?

Answer 1

You have to take new version number from web service.This is because if you want to update app from app store then you just need to increase your app version from your pannel and you will get it in web service and then you can check it like this (call this method by passing web service version) :-

(BOOL)isUpdateAvailable:(NSString*)latestVersion 
{ 
    NSString *currentAppVersion = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];

    NSArray *myCurrentVersion = [currentAppVersion componentsSeparatedByString:@"."];
    NSArray *myLatestVersion = [latestVersion componentsSeparatedByString:@"."];
    NSInteger legthOfLatestVersion = myLatestVersion.count;
    NSInteger legthOfCurrentVersion = myCurrentVersion.count;
    if (legthOfLatestVersion == legthOfCurrentVersion)
    {
        for (int i=0; i<myLatestVersion.count; i++)
        {
            if ([myCurrentVersion[i] integerValue] < [myLatestVersion[i] integerValue])
            {
                return true;
            }
            else if ([myCurrentVersion[i] integerValue] == [myLatestVersion[i] integerValue])
            {
                continue;
            }
            else
            {
               return false;
            }
        }
        return false;
    }
    else
    {
        NSInteger count = legthOfCurrentVersion > legthOfLatestVersion ? legthOfLatestVersion : legthOfCurrentVersion;
        for (int i=0; i<count; i++)
        {
            if ([myCurrentVersion[i] integerValue] < [myLatestVersion[i] integerValue])
            {
                return true;
            }
            else if([myCurrentVersion[i] integerValue] > [myLatestVersion[i] integerValue])
            {
                return false;
            }
            else if ([myCurrentVersion[i] integerValue] == [myLatestVersion[i] integerValue])
            {
                continue;
            }
        }

        if (legthOfCurrentVersion < legthOfLatestVersion)
        {
            for (NSInteger i=legthOfCurrentVersion; i<legthOfLatestVersion; i++)
            {
                if ([myLatestVersion[i] integerValue] != 0)
                {
                    return YES;
                }
            }
            return NO;
        }
        else
        {
            return NO;
        }
    }
}

This will return bool value if it will return YES then you will have new version of your app and if NO then your app has updated version.