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iOS Solution: Tower Defense Game

Can I please get help with this proactice project

I was putting in my solution into the playground, this is what I typed:

let distanceBetweenX = towerX - enemyX
let squaredXDistance = distanceBetweenX * distanceBetweenX

let distanceBetweenY = towerY - enemyY
let squaredYDistance = distanceBetweenY * distanceBetweenY

let sumOfSquares = squaredXDistance + squaredYDistance

The results for 4 of the constants did not print in the REPL. Only for the first constant. I also received an error in the debug area:

libc++abi.dylib: terminating with uncaught exception of type NSException

I am using Swift 4. Can someone please explain why this did not work in my IDE?

Also, I feel like the jump from learning the operators to jumping right into such complex arimathic solutions was rather jarring and overwhelming. Thank you.

1 Answer

Meg Dooley
Meg Dooley
7,321 Points

Hi Ellis

I copied your code into my more recent version of Xcode (10.0) and it worked fine so it might be a bug? Also - I often get overwhelmed by the math based challenges too so I usually spend some time googling the arithmetic needed before I attempt them. I felt a bit disheartened at first that I had to do that but there's really no need to be, most of us haven't even thought about math since we left school after all! I also find it handy to write down useful math formulas as they come up and post them to my desktop or sometimes on post-it notes on the wall behind my laptop so i can easily remind myself of what to do if I need it for a future code challenge. Hope that helps!