Question

OK, I’m not seriously looking to use some sort of exit command to quit the loop, but in this situation, I tend to use two methods, when I’m sure I could use one.

With this example, what is the best approach ?

typedef enum {
    FirstParamHigherThanSecond,
    FirstParamLowerThanSecond,
    ParamsEqual
} VersionStatus;

VersionStatus compareVersions(NSString* left, NSString* right) {

    VersionStatus retVal;

    NSComparisonResult res = analyszeVersions(left, right);
    if (res == NSOrderedSame) {
        retVal = ParamsEqual;

    } else if (res == NSOrderedDescending) {
        retVal = FirstParamHigherThanSecond;

    } else if ( res == NSOrderedAscending) {
        retVal = FirstParamLowerThanSecond;
    }
    return retVal;
}

.

NSComparisonResult analyszeVersions(NSString* leftVersion, NSString* rightVersion)
{
    int i;

    NSMutableArray *leftFields  = [[NSMutableArray alloc] initWithArray:[leftVersion  componentsSeparatedByString:@"."]];
    NSMutableArray *rightFields = [[NSMutableArray alloc] initWithArray:[rightVersion componentsSeparatedByString:@"."]];

    if ([leftFields count] < [rightFields count]) {
        while ([leftFields count] != [rightFields count]) {
            [leftFields addObject:@"0"];
        }
    } else if ([leftFields count] > [rightFields count]) {
        while ([leftFields count] != [rightFields count]) {
            [rightFields addObject:@"0"];
        }
    }

    for(i = 0; i < [leftFields count]; i++) {
        NSComparisonResult result = [[leftFields objectAtIndex:i] compare:[rightFields objectAtIndex:i] options:NSNumericSearch];
        if (result != NSOrderedSame) {
            return result;
        }
    }
    return NSOrderedSame;
}

Answer 1

If I understand your question correctly, you could just use a while loop instead of your for loop, like:

i = 0;
NSComparisonResult result;
while (i < [lefFields count]  &&  
       NSOrderedSame == (result = [[leftFields objectAtIndex:i] compare:[rightFields objectAtIndex:i] options:NSNumericSearch]))
    ++i;
return result;