SOLVED: Day 6 Checkpoint 3: while loops question 8

@spinhead

Jun '23

I get 4 lines, not 5. What am I missing?

var number: Int = 10
while number > 0 {
    number -= 2
    if number % 2 == 0 {
        print("\(number) is an even number.")
    }
}

number is 10, subtract 2, number is 8, prints 8 is an even number (line 1)
subtract 2, number is 6, prints 6 etc (line 2)
-2 = 4, prints 4 is etc (line 3)
-2 = 2, prints 2 is an even number (line 4)

-2 = 0, number is NOT > 0; end

@roosterboy HWS+

Jun '23

Have you run it or only tried working it out in your head? It prints 5 lines because number does not get decremented to 0 until you are already inside the loop, past the check, when number == 2.

So, it's:

number is 10, while condition passes, subtract 2, number is 8, prints 8 is an even number (line 1)
number is 8, while condition passes, subtract 2, number is 6, prints 6 etc (line 2)
number is 6, while condition passes, subtract 2, number is 4, prints 4 etc (line 3)
number is 4, while condition passes, subtract 2, number is 2, prints 2 etc (line 4)
number is 2, while condition passes, subtract 2, number is 0, prints 0 etc (line 5)
number is 0, while condition fails, end of loop

@spinhead

Jun '23

number does not get decremented to 0 until you are already inside the loop

perfect. brain fog day; knew I was missing something obvious.

yes, working it in my head, not running it.

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