Iterating enum cases with CaseIterable in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to make the enum conform to CaseIterable.

Swift

enum Direction: [1] {
    case north, south, east, west
}

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ACaseIterable

BCodable

CEquatable

DHashable

Attempts:

3 left

💡 Hint

Common Mistakes

Using other protocols like Codable or Equatable which do not provide case iteration.

To iterate over all enum cases, the enum must conform to CaseIterable.

2fill in blank

medium

Complete the code to print all cases of the enum.

Swift

for direction in Direction.[1] {
    print(direction)
}

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Acases

Bvalues

CallCases

Delements

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect property names like 'cases' or 'values' which do not exist.

The CaseIterable protocol provides the allCases property to access all enum cases.

3fill in blank

hard

Fix the error in the code to correctly iterate over enum cases.

Swift

enum Color: CaseIterable {
    case red, green, blue
}

for color in Color.[1]() {
    print(color)
}

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AallCases

BallCases()

Ccases

Dall_cases

Attempts:

3 left

💡 Hint

Common Mistakes

Calling allCases with parentheses like a function.

allCases is a property, not a method, so it should not have parentheses.

4fill in blank

hard

Fill both blanks to create a dictionary with enum case names as keys and raw values as values.

Swift

enum Fruit: String, CaseIterable {
    case apple = "Red"
    case banana = "Yellow"
    case grape = "Purple"
}

let fruitColors = [[1]: [2] for fruit in Fruit.allCases]

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Afruit.rawValue

Bfruit

Cfruit.name

Dfruit.description

Attempts:

3 left

💡 Hint

Common Mistakes

Using fruit.name or fruit.description which do not exist.

Use the enum case itself as the key and its rawValue as the value.

5fill in blank

hard

Fill all three blanks to filter enum cases with raw value length greater than 5 and create a list of their names.

Swift

enum Vehicle: String, CaseIterable {
    case car = "Auto"
    case motorcycle = "Motorcycle"
    case bicycle = "Bike"
    case airplane = "Airplane"
}

let longNames = [[1] for vehicle in Vehicle.allCases if [2].[3] > 5]

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Avehicle.rawValue

Bcount

Cvehicle

Attempts:

3 left

💡 Hint

Common Mistakes

Using the enum case itself instead of raw values.

Checking length on the enum case instead of the raw value.

We want the raw value names where the length is greater than 5. So we use vehicle.rawValue in the list and check vehicle.rawValue.count > 5.