Setting variable equal to if statement condition

Question

I have an if statement that checks to see if an array element matches a local variable.

 if pinArray.contains(where: {$0.title == restaurantName})

How would I create a variable of this element? I attempted

 let thePin = pinArray.contains(where: {$0.title == restaurantName})

but this comes with "could not cast boolean to MKAnnotation".

I also tried variations of

let pins = [pinArray.indexPath.row]
let pinn = pins(where: pin.title == restaurantName) (or close to it)

mapp.selectAnnotation(thePin as! MKAnnotation, animated: true)

to no avail. What basic step am I missing?

If you actually have code such as if pinArray.contains(where: {$0.title == restaurantName}) { // some stuff } then you can definitely replace that with let thePin = pinArray.contains(where: {$0.title == restaurantName}) followed by if thePin { // some stuff }. — rmaddy
– rmaddy, Commented Jul 7, 2018 at 6:13
Happen to see anything in the update that is causing the signal sibart? — Jonathan Gardocki
– Jonathan Gardocki, Commented Jul 7, 2018 at 6:19
Why are you attempting to force-cast a Bool to a MKAnnotation? thePin is a Bool indicating whether the array contains the value or not. — rmaddy
– rmaddy, Commented Jul 7, 2018 at 6:21
I was attempting to create a variable that is equal to the pin of the pinArray that is equal to/has the same title as restaurantName. — Jonathan Gardocki
– Jonathan Gardocki, Commented Jul 7, 2018 at 6:23

rmaddy · Accepted Answer · 2018-07-07 06:26:38Z

1

contains(where:) returns a Bool indicating whether a match was found or not. It does not return the matched value.

So thePin is a Bool which you then attempt to force-cast to a MKAnnotation which of course crashes.

If you want the matching value, change your code to:

if let thePin = pinArray.first(where: { $0.title == restaurantName }) {
    do {
        mapp.selectionAnnotation(thePin, animated: true)
    } catch {
    }
} else {
    // no match in the array
}

No need for contains at all. No need to cast (assuming pinArray is an array of MKAnnotation).

answered Jul 7, 2018 at 6:26

rmaddy

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2 Comments

Jonathan Gardocki Over a year ago

I have to ask, you've helped me throughout several projects - thanks, haha - but how have you come to know so much? Also, in the if let statement, "first" refers to the first element that matches restaurantName?

rmaddy Over a year ago

Yes, it's the first match. See the documentation for first(where:). And I've been programming since 1979.

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