CODEWITHSUNDEEP
swiftenumsswitch-statement
Sean
Sean

Reputation: 490

Why struct can use 'switch case'?

Looking at the below code:

public override func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
    
    if let urlError = error as? URLError {
        switch urlError.code {
        case .cancelled:
            print("cancelled")
        case .badURL:
            print("badURL")
        default:
            break
        }
    }
}

The first question:

URLError hasn't a property code. It only has a public Struct Code.

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So why can use urlError.code.

The second question: URLError.Code is a struct. It has many static property, the code likes below:

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It isn't an enum. So why can use syntax case .cancelled:.

Upvotes: 2

Views: 839

Answers (1)

Vadim Nikolaev
Vadim Nikolaev

Reputation: 2132

So why can use urlError.code

According to documentation Error conforms type NSError and NSError has property code, that's why you can use code

It isn't an enum

urlError.code has type URLError.Code and this type conforms protocol RawRepresentable (you can read about it here), that's why you can use switch-case as for enum

Upvotes: 1

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