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

Posted by Eddie Aguilar
Eddie Aguilar
2,393 Points

I am literally stuck and cannot even think of what I am supposed to write. HELP??

I have watched the all of the content leading up to this point and have a basic understanding of it so far. But for this challenge I cannot, whatsoever think of what I am supposed to write. I have watched the 2 videos prior to this challenge about 4 times and have a decent understanding of it. Again for this challenge, I cannot move forward and was wondering I could have someone give me somewhat of a walkthrough.

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

for n in 1...100 {
    // Enter your code below
    NO IDEA WHAT TO WRITE
    // End code 
}

1 Answer

andren
andren
28,558 Points
andren
andren
28,558 Points

Sure I can provide a step by step walkthrough.

The first thing you have to do in this task is figure out if the number in n is odd. In an earlier lecture you were shown that you can use the % remainder (modulus) operator to figure out if something is even.

if you divide a number by 2 and it has a remainder of 0 then it is even. If you use the != (not equal) operator like this n % 2 != 0 you will check if a number is not even. If a number is not even then it must be odd.

The second thing you need to do is check that n is a multiple of 7. This can also be accomplished using the remainder operator. If the remainder of n and 7 is 0 then n has to be a multiple of seven.

So the first line of loop should look like this:

var results: [Int] = []

for n in 1...100 {
    if n % 2 != 0 && n % 7 == 0 { // Checks if n is both an odd number and a multiple of seven
    }
}

All that is left to do after that is to append n to the results array. That can be done pretty simply by using the append method. I'll illustrate below:

var results: [Int] = []

for n in 1...100 {
    if n % 2 != 0 && n % 7 == 0 { // Checks if n is both an odd number and a multiple of seven
        results.append(n) // Append n to the results array
    }
}

And that is actually all you have to do, the above code will add odd numbers that are multiples of seven to the results array.