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iOS Object-Oriented Swift Properties Optional Property

andrew park
andrew park
2,733 Points
Posted by andrew park
andrew park
2,733 Points

Both these work on my playground should I use the second celsius = (newValue + 32)/1.8 celsius = newValue

The second didn't work on your challenge but did on my playground !

2 Answers

Victor Naumik
Victor Naumik
2,423 Points
Victor Naumik
Victor Naumik
2,423 Points

You're setting a temperature.fahrengeit = ... If you simply assign it to celsius - it will be wrong.

The challenge checks for it, and the playground doesn't - cause it doesn't know anything about units of temperature or whatever, just the validity of code.

I mean - your code is valid, but it's wrong physically.

Dan Chambers
Dan Chambers
6,057 Points
Dan Chambers
Dan Chambers
6,057 Points

The code is definitely not valid - you should get the error within your playground "Cannot assign to the result of this expression". If you are not then Xcode has probably crashed. Save out and reload, and the error should then show.

A good tip to spot when this has happened (as it has countless times to me throughout this course). Is when the results column stops updating. In your particular example, if you tried to assign a new value to Fahrenheit, you would notice that nothing updates.