Protocol composition in practice in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable that conforms to both protocols.

Swift

protocol Drivable {
    func drive()
}

protocol Flyable {
    func fly()
}

var vehicle: [1]

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

ADrivable | Flyable

BDrivable & Flyable

CDrivable, Flyable

DDrivable or Flyable

Attempts:

3 left

💡 Hint

Common Mistakes

Using | instead of & for protocol composition.

Separating protocols with commas or words like 'or'.

In Swift, protocol composition uses the & symbol to require conformance to multiple protocols.

2fill in blank

medium

Complete the function parameter type to accept any object conforming to both protocols.

Swift

func operate(vehicle: [1]) {
    vehicle.drive()
    vehicle.fly()
}

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

ADrivable & Flyable

BDrivable, Flyable

CDrivable | Flyable

DDrivable or Flyable

Attempts:

3 left

💡 Hint

Common Mistakes

Using | instead of & in parameter types.

Using commas or words like 'or' instead of &.

The function parameter type uses protocol composition with & to require both protocols.

3fill in blank

hard

Fix the error in the variable declaration to use protocol composition correctly.

Swift

var gadget: [1]

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

ADrivable, Flyable

BDrivable | Flyable

CDrivable & Flyable

DDrivable or Flyable

Attempts:

3 left

💡 Hint

Common Mistakes

Using | or commas instead of &.

Writing 'or' instead of &.

Protocol composition requires the & symbol, not | or commas.

4fill in blank

hard

Fill both blanks to create a function that accepts an object conforming to two protocols and calls their methods.

Swift

func performAction(on item: [1]) {
    item.[2]()
}

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

ADrivable & Flyable

Bdrive

Cfly

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Calling a method not defined in the protocols.

Using incorrect protocol composition syntax.

The function parameter uses protocol composition, and the method called is drive().

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps names to objects conforming to two protocols, filtering by a condition.

Swift

let fleet = ["car": carObj, "plane": planeObj]
let activeFleet = fleet.filter { $0.value is [1] }
    .mapValues { $0 as! [2] }
    .filter { $0.value.[3]() }

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

ADrivable & Flyable

Cdrive

Dfly

Attempts:

3 left

💡 Hint

Common Mistakes

Using only one protocol instead of composition.

Calling a method not defined in the protocols.

The filter checks if the value conforms to both protocols, then casts it, and finally calls fly() method.