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iOS Generics in Swift Generics and Protocols Extending Generic Types

Stanislav Zaichenko
Stanislav Zaichenko
iOS Development with Swift Techdegree Student 4,929 Points

Ive got solution working in my sandbox however it wont pass through compiler error here in code challenge

The error says String has no member "contains", I tried the older Swift range(of: prefix) and same error.

the attached code is working in sandbox

protocol PrefixContaining { func hasPrefix(_ prefix: String) -> Bool }

extension String: PrefixContaining { func hasPrefix(_ prefix: String) -> Bool { if (self.contains(prefix)) { return true } return false } }

// Enter code below extension Array where Element: PrefixContaining { func filter(byPrefix prefix: String) -> [Element] { var result: [Element] = [] for (_, element) in self.enumerated() { if element.hasPrefix(prefix) { result.append(element) } } return result } }

var myArray = ["abnmmm", "nsbf", "sdfsdf", "absmdnfsdf"] myArray.filter(byPrefix: "ab")

1 Answer