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

Why are these logical conditions not working for my if-loop?

The error is reading: Bummer! Make sure you are performing logical checks in the condition of the if statement, however, I thought variables representing boolean values would be valid logical checks.

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

for n in 1...100 {
    // Enter your code below
    var even: Boolean = (0 == n % 2) 
    var isDivisible: Boolean = (0 == n % 7) 
    if !even && isDivisible {
    results.append(n)
    }
    // End code 
}

2 Answers

andren
andren
28,558 Points

Separating the conditions into variables is not strictly necessary, but you are right that doing so is a completely valid way of completing this task. The error message Treehouse gives can often be a bit misleading, it is often more helpful to look at the errors that the Swift compiler generates, which you can do by clicking on the "Preview" button after running your code.

For your code the error messages generated is this:

swift_lint.swift:10:15: error: use of undeclared type 'Boolean'
    var even: Boolean = (0 == n % 2) 
              ^~~~~~~
swift_lint.swift:11:22: error: use of undeclared type 'Boolean'
    var isDivisible: Boolean = (0 == n % 7) 
                     ^~~~~~~

The thing those messages point out is that Swift does not recognize the word Boolean as a type, that is because the type for Boolean variables in swift is actually the word Bool.

So if you replace Boolean with Bool like this:

var results: [Int] = []

for n in 1...100 {
    // Enter your code below
    var even: Bool = (0 == n % 2) 
    var isDivisible: Bool = (0 == n % 7) 
    if !even && isDivisible {
    results.append(n)
    }
    // End code 
}

Then your code will work.

Jonathan Ruiz
Jonathan Ruiz
2,998 Points

Hi Charles this is a great way to approach this ! your very very close all you need to do is take out the part where you reference the type Boolean for the variables and it'll pass

var even = (0 == n % 2)