The count in my For loop is not incrementing

Question

When running my code, I am getting a number of 1's printing to the console rather than 1,2,3,4,5....

Some help with why this is happening would be great, I'm having trouble figuring it out.

The idea is to loop through the Calendar names until finding the 'Travel' calendar.

func checkCalendarExists(){
    var eventCalendars = store.calendarsForEntityType(EKEntityTypeEvent) as [EKCalendar]

    for i in eventCalendars {

        var count = 0
        var calendarCount = eventCalendars.count

        if i.title != "Travel" && count != calendarCount
        {
            ++count
            println(count)
        }

        else if i.title == "Travel"
        {
            // do something
        }
        else
        {
           aMethod()
        }

    }
}

score 2 · Accepted Answer · answered Jun 18 '15 at 18:46

2

Your count variable is not being incremented because it is declared inside the loop and initialized to the value zero at the beginning of each iteration. For your code to work as expected you have to move var count = 0 outside the for loop.

answered Jun 18 '15 at 18:46

ALXGTV

362
3
12

score 1 · Answer 2 · answered Jun 18 '15 at 18:53

1

Your count variable does get incremented, but it resets to zero every time the for loop runs its sequence.

It's always advised to declare and assign incrementing variables outside loops.

Please change your code to (I am initializing var count = 0 before the loop)

    func checkCalendarExists(){
        var eventCalendars = store.calendarsForEntityType(EKEntityTypeEvent) as [EKCalendar]

        var count = 0
        for i in eventCalendars {

            var calendarCount = eventCalendars.count
        ......
        ......
        ......
        else
        {
           aMethod()
        }
    }
}

answered Jun 18 '15 at 18:53

user3337714

663
1
7
25

thank you, so obvious *embarassed face*. sorry I can't vote up- I don't have enough rep – Yelims01 Jun 18 '15 at 19:02
@Yelims01 You don't need to be embarrassed or sorry. Next time try reasoning through your code and google step. I hope you will be able to help some other newbies. – user3337714 Jun 18 '15 at 19:12

score 0 · Answer 3 · answered Jun 18 '15 at 19:14

ALXGTV's answer explains why you have that unexpected behavior.

Your code can be optimized though - rather than manually handling a counter variable, I recommend using the enumerate function, which returns a (index, value) at each iteration:

for (index, calendar) in enumerate(eventCalendars) {
    ...
}

Also this variable:

var calendarCount = eventCalendars.count

is populated at each iteration, always with the same value. It would be more efficient if it is moved before the loop, making it immutable:

let calendarCount = eventCalendars.count
for (index, calendar) in enumerate(eventCalendars) {
    ...
}

Last, I would prefer using a flag for the not found condition, handling it outside the loop:

func checkCalendarExists() {
    var eventCalendars = store.calendarsForEntityType(EKEntityTypeEvent) as [EKCalendar]    
    var found = false
    let calendarCount = eventCalendars.count
    for (index, calendar) in enumerate(eventCalendars) {
        if calendar.title == "Travel" {
            // do something
            found = true
            break // This stops the loop
        } else {
            println(index + 1)
        }
    }

    if !found {
        aMethod()
    }
}

The count in my For loop is not incrementing

3 Answers3