Protocol conformance via extension in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to make the struct conform to the protocol by adding the required property.

Swift

protocol Describable {
    var description: String { get }
}

struct Car: Describable {
    var make: String
    var model: String
    var description: String {
        return [1]
    }
}

Drag options to blanks, or click blank then click option'

Adescription

Bprint(make)

Cmake + model

D"\(make) \(model)"

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a print statement instead of a string.

Using the property name 'description' inside itself causing recursion.

The description property must return a String. Using a string interpolation with make and model correctly returns the description.

2fill in blank

medium

Complete the extension to make Int conform to the protocol by implementing the required method.

Swift

protocol Squarable {
    func squared() -> Int
}

extension Int: Squarable {
    func squared() -> Int {
        return [1]
    }
}

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Aself * self

Bself + self

Cself / self

Dself - self

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition or subtraction instead of multiplication.

Dividing the number by itself which always returns 1.

To return the square of the integer, multiply self by self.

3fill in blank

hard

Fix the error in the extension to correctly conform to the protocol by implementing the required computed property.

Swift

protocol Identifiable {
    var id: String { get }
}

struct User {
    var name: String
}

extension User: Identifiable {
    var [1]: String {
        return name
    }
}

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Aid

Bidentifier

Cname

DuserId

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different property name than the protocol requires.

Not implementing the property at all.

The protocol requires a property named 'id'. The extension must implement 'id' to conform.

4fill in blank

hard

Fill both blanks to complete the extension that makes Array conform to the protocol by implementing the required method.

Swift

protocol Summable {
    func sum() -> Int
}

extension Array: Summable where Element == Int {
    func sum() -> Int {
        return self.[1](0) { $0 [2] $1 }
    }
}

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Areduce

B+

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using * or - instead of + for summing.

Using map or filter instead of reduce.

The reduce method with initial 0 and + operator sums all elements in the array.

5fill in blank

hard

Fill all three blanks to complete the extension that makes String conform to the protocol by implementing the required computed property and method.

Swift

protocol TextRepresentable {
    var text: String { get }
    func shout() -> String
}

extension String: TextRepresentable {
    var [1]: String {
        return self
    }
    func [2]() -> String {
        return self.[3]()
    }
}

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Atext

Bshout

Cuppercased

Dlowercased

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong property or method names.

Using 'lowercased()' instead of 'uppercased()' for shout.

The property 'text' returns self. The method 'shout' returns the uppercase version using 'uppercased()'.