How to combine two NSString?

I have the following two NSString:

NSString *latitudeString, *longitudeString;

latitudeString = @"50.1338";

and

longitudeString = @"8.91583";

What I want to obtain is a NSString that looks like this: 50.1338,8.91583.

How do I obtain that?Thanks

IMPORTANT: The values I showed are only for the purpose of better understanding, ussually latitudeString and longitudeString have random values.