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iOS Swift Collections and Control Flow Control Flow With Conditional Statements Working With Logical Operators

Denny Louis
Denny Louis
10,885 Points

Am I doing something wrong?

I'm getting a message when I submit my code saying "Make sure you're appending the correct values to the results array in order to pass the challenge".

I've tested my code in a Swift Playground and it doesn't say I have any errors and the results array has all of the values inside, not sure what I am doing wrong?

operators.swift
var results: [Int] = []

for n in 1...100 {
    // Enter your code below
    if n % 2 != 0 && n % 7 == 0 {
      results += [n]
    }
    // End code 
}

3 Answers

Jason Anders
MOD
Jason Anders
Treehouse Moderator 145,860 Points

Hey Denny,

The loop will return a single Integer every time it iterates through itself, so nstead of using the unary operator += to add what would need to be another array to the results array, try using the .append method. :)

Keep Coding! :dizzy:

Denny Louis
Denny Louis
10,885 Points

Hey Jason, thank you for your answer, the append method worked.

Are you able to explain why the append method worked, but concatenation wasn't accepted? I'd just like to know so I don't make the mistake again. It's pretty confusing since it worked for me in Xcode.

Thanks!

Jason Anders
Jason Anders
Treehouse Moderator 145,860 Points

Hey Denny,

It does work in Xcode's playground, and as far as I can tell, it's valid syntax and produces the same result.

In this instance, however,I think it's probably just the code checker for the challenge being picky and particular to a certain way (here the .append method).

But I would like Pasan Premaratne to just confirm please. :)

Pasan Premaratne
STAFF
Pasan Premaratne
Treehouse Teacher

Denny Louis

Indeed it is the solution checker ensuring that you use append here. I'll update this to include concatenation

John Wilcox
John Wilcox
4,233 Points

Hi, I'm having the same issue today. Could the simulator still be updated to include concatenation, or could the question be updated to steer the user away from concatenation?

Pasan Premaratne
Pasan Premaratne
Treehouse Teacher

Hey John,

Could you post what error you're specifically getting when you use concatenation. It should work but I might be missing a particular variation