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

Neymat Kakar
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Neymat Kakar
iOS Development Techdegree Student 786 Points
Posted by Neymat Kakar
.a{fill-rule:evenodd;}techdegree
Neymat Kakar
iOS Development Techdegree Student 786 Points

collections and control flow

For this challenge, we'd like to know in a range of values from 1 to 100, how many numbers are both odd, and a multiple of 7.

To start us off, I've written a for loop to iterate over the desired range of values and named the local constant n. Your job is to write an if statement inside the for loop to carry out the desired checks.

If the number is both an odd number and a multiple of 7, append the value to the results array provided.

Hint: To check for an odd number use the not operator to check for "not even"

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

for n in 1...100 {
    // Enter your code below

    // End code 
}

2 Answers

Hannah Gaskins
Hannah Gaskins
14,572 Points
Hannah Gaskins
Hannah Gaskins
14,572 Points

Hey there Neymat,

What you'll want to do here combine logical operators and control flow. Here specifically we will be using the AND logical operator to see if n is both odd and a multiple of 7, and the not logical operator because odd numbers are not divisible by 2. On top of this we are using the modulus to ensure the remainder is or is not 0. Additionally we will use an if conditional statement to ensure our checks are true. If they are true we will then use the append method on the array there to add them to a list. Here is how I did this: 

var results: [Int] = []

for n in 1...100 {
    if n % 2 != 0 && n % 7 == 0 {
      results.append(n)
    }
}

Hope this helps!

Cheers ,

vetahccsob
vetahccsob
7,345 Points

Hi Hannah Gaskins, I tried your solution and it's telling me it's incorrect?

It says "Make sure you are performing logical checks in the condition of the if statement"

Also thank you for your help!

Hannah Gaskins
Hannah Gaskins
14,572 Points
Hannah Gaskins
Hannah Gaskins
14,572 Points

Hey there Derrick,

Hmmmm, I checked again - literally copy pasting the above code into the challenge - and it worked on my end.

The logical checks piece of the error message makes me think there may be issue with the && operator. You can also read more about logical operators in the guide here under Logical Operators headline:

Basic Operators Guide from Apple

I'd also check the != and == operators there as well just to be sure.

If you are also literally copy pasting the code and getting an error I would clear your browser cache and try in a new browser to see if you are having the same troubles. Sometimes Treehouse can be buggy.

Hope that helps!