do you have any idea what should i do ? You should show your code.

Why don't you simply access the property uuid? for result in results as! [HKQuantitySample] { let uuid = result.uuid print(uuid) let bloodGlucose = result.quantity.description //... } By the way, what is the type of results? You should better avoid risky forced casting as! as far as you can.

I cannot show the all code  I see. Hope your issue will be fixed soon. Good luck.

Can you show enough code for examining what's happening? Simplified full code which builds and runs would be welcome.

how can i define it ? You can find many articles defining strrev, but it would be better for you to do it by yourself if you are learning C-programming.

what should i do ? strrev is not a Standard C function and is not included in the libraries provided with Xcode. You may need to define it by yourself.

there is a error that keeps popping up on line 17. you should show all the error messages.

I'm having the same problem. I tried your work around and it didn't work.  Better start your own thread with enough code to reproduce your issue.

What do you mean by will not work? If your code causes build time errors, you should show all the error messages. If your code causes runtime errors, you should include all the error info as well as all the steps to reproduce the error. If your code runs without errors but generates unexpected results, you need to clarify what you expect, what you actually get and how you can reproduce the issue.

Depends on the Swift code you want to use. Some swift codes cannot be exposed to ObjC. If you are going to write a new Swift class from now on, it is not so difficult to write an ObjC compatible Swift class.