CODEWITHSUNDEEP
iosswift
teachMeSenpai
teachMeSenpai

Reputation: 236

What is the proper way to use if _ is _ or .isKind(of: )

I've been struggling to implement this piece of code. I'm converting some legacy code over to swift and I can't get the equivalent of [annotation isKindofClass] to work.

Originally I went with something like (gave me errors 

mapView.annotations.forEach {
        if !$0.isKind(of: MKUserLocation) {
            self.mapView.removeAnnotation($0)
        }
    }

But I read on this post that swift had a different way of doing it. 

mapView.annotations.forEach {
        if !$0 is MKUserLocation {
            self.mapView.removeAnnotation($0)
        }
    }

this one gives me the error: Cannot convert value of type MKAnnotation to expected argument type BOOL

Upvotes: 1

Views: 231

Answers (2)

Shehata Gamal
Shehata Gamal

Reputation: 100523

In short you can do With

mapView.annotations.remove(where:{ !($0 is MKUserLocation) } )

Upvotes: 1

kientux
kientux

Reputation: 1792

public func isKind(of aClass: AnyClass) -> Bool

This function requires AnyClass as argument, you must pass a class, using .self

    mapView.annotations.forEach {
        if !$0.isKind(of: MKUserLocation.self) {
            self.mapView.removeAnnotation($0)
        }
    }

When use is, you must wrap the expression with parentheses:

    mapView.annotations.forEach {
        if !($0 is MKUserLocation) {
            self.mapView.removeAnnotation($0)
        }
    }

You are checking boolean value of $0, not the is expression, hence the error.

Upvotes: 2

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