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iOS Swift Collections and Control Flow Control Flow With Conditional Statements FizzBuzz Challenge

Kenneth Dubroff
Kenneth Dubroff
10,612 Points
Posted by Kenneth Dubroff
Kenneth Dubroff
10,612 Points

Int compared to Bool

in the fizzbuzz challenge, I'm using a comparative operator to check for a remainder of 0. When I do this, swift returns a Bool, but an Int is expected in order to compile. I get something like an Int can't be matched to a Bool

fizzBuzz.swift 
func fizzBuzz(n: Int) -> String {
  // Enter your code between the two comment markers
  switch n {
  case n % 3 == 0: return "Fizz"
  case n % 5 == 0: return "Buzz"
  }
  // End code
  return "\(n)"
}

5 Answers

Alexander Davison
Alexander Davison
65,469 Points
Alexander Davison
Alexander Davison
65,469 Points

You can remove the n in the switch (n) { line of code, so that your code looks like this:

func fizzBuzz(n: Int) -> String {
  // Enter your code between the two comment markers
  switch {
  case n % 3 == 0: return "Fizz"
  case n % 5 == 0: return "Buzz"
  }
  // End code
  return "\(n)"
}

Just note that I am not 100% familiar with Swift, but at least in Ruby you are allowed to do this. If this method doesn't work, you can use an if/else if/else clause.

I hope this helps :grin:

:dizzy: ~Alex :dizzy:

Kenneth Dubroff
Kenneth Dubroff
10,612 Points
Kenneth Dubroff
Kenneth Dubroff
10,612 Points

Thanks for the input, Alex.

That doesn't work in Swift, as an argument is required after switch. It also doesn't do anything to address the Int/Bool issue

Alexander Davison
Alexander Davison
65,469 Points

Sorry for not explaining :unamused:

I was kinda lazy on the answer :laughing:

Anyway, you shouldn't use a switch statement for this challenge.

You use the switch statement like this:

switch a {
  case 0: print("Zero!")
  case 1: print("One is fun!")
  case 2: print("Two is true!")
  case 3: print("Three for me!")
  default: print("I don't know that one...")
}

In this code...

  • If a is 0, this will print "Zero!"
  • If a is 1, this will print "One is fun!"
  • If a is 2, this will print "Two is true!"
  • And so on...

As you see, you don't need a condition for the cases. It automatically checks if the focused variable (in my code a) is the value after case. In Ruby, you can specify no variable to focus on and enter conditions after each case statement instead of a number. Since I'm unfamiliar with Swift, I'm not sure if you can do this.

Use a if/else if/else condition instead.

EDITED MAJOR INFORMATION, PLEASE RE-READ

Mel John del Barrio
seal-mask
.a{fill-rule:evenodd;}techdegree
Mel John del Barrio
iOS Development Techdegree Student 8,484 Points
Mel John del Barrio
.a{fill-rule:evenodd;}techdegree
Mel John del Barrio
iOS Development Techdegree Student 8,484 Points

Try using the where clause for the conditions that needs to match with your n

let yetAnotherPoint = (1, -1)
switch yetAnotherPoint {
case let (x, y) where x == y:
    print("(\(x), \(y)) is on the line x == y")
case let (x, y) where x == -y:
    print("(\(x), \(y)) is on the line x == -y")
case let (x, y):
    print("(\(x), \(y)) is just some arbitrary point")
}
// Prints "(1, -1) is on the line x == -y"
Kenneth Dubroff
Kenneth Dubroff
10,612 Points
Kenneth Dubroff
Kenneth Dubroff
10,612 Points

Alex, I'd love to use if/then statements since I understand the syntax perfectly well. However, this challenge is specifically to use switch. Switch can accept arguments and is much more powerful than if/else. The syntax is just different

Kenneth Dubroff
Kenneth Dubroff
10,612 Points
Kenneth Dubroff
Kenneth Dubroff
10,612 Points

Mel John del Barrio hit the nail on the head with syntax. That said, though it compiles, the challenge doesn't accept my answer.

Am I correct in that n %3 == 0 should be checking if n is divisible by 3?

my code looks like this:

  switch n {
  case let n where n % 3 == 0: return "Fizz"
  case let n where n % 5 == 0: return "Buzz"
  case let n where n % 3 == 0 && n % 5 == 0: return: "FizzBuzz"
  }

I had to enter a default case in order for the compiler to accept the switch statement, though the challenge says not to enter a default case

Kenneth Dubroff
Kenneth Dubroff
10,612 Points
Kenneth Dubroff
Kenneth Dubroff
10,612 Points

Accepted answer: (precedence matters!) The compiler stopped at let n % 3 == 0 and didn't check if the number was divisible by both 3 and 5 because the condition was satisfied. I had to move the line checking for both 3 and 5 to the top. Also, though the challenge specifically asks not to enter a default case, one MUST be entered. 

func fizzBuzz(n: Int) -> String {
    // Enter your code between the two comment markers
switch n {
    case let n where n % 3 == 0 && n % 5 == 0: return "FizzBuzz"  
    case let n where n % 3 == 0: return "Fizz"
    case let n where n % 5 == 0: return "Buzz"
    default: return "\(n)"
}
// End code
return "\(n)"
}
Kenneth Dubroff
Kenneth Dubroff
10,612 Points
Kenneth Dubroff
Kenneth Dubroff
10,612 Points

Hard to pick a best answer here. Alex's answer of using if/else is actually correct, and the most common solution. However, the code I used (Mel John del Barrio's example) performs the same function, and uses less lines of code. It's also less characters per line of code, leaving less room for syntax/spelling errors.

In my defense, the lesson went over switch vs if/else and specifically stated that switch is basically better (more powerful). Using a combination of if/else and switch seems clunky and unnecessary

At any rate, thanks to both of you. Not sure if a mod will pick best answer since I'm undecided, but may the victor take the spoils!