Enums with associated values in iOS Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an enum with an associated value.

iOS Swift

enum Vehicle {
  case car([1]: String)
}

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

Amodel

Bspeed

Ccolor

Dyear

Attempts:

3 left

💡 Hint

Common Mistakes

Using a type name instead of a label for the associated value.

Omitting the label before the colon.

The enum case car has an associated value named model of type String.

2fill in blank

medium

Complete the code to extract the associated value from the enum using a switch statement.

iOS Swift

let vehicle = Vehicle.car(model: "Sedan")
switch vehicle {
case .car(let [1]):
  print("Model is \(model)")
}

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

Atype

Bname

Cmodel

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name than the associated value label.

Forgetting to use let to bind the value.

The let model extracts the associated value labeled model from the enum case.

3fill in blank

hard

Fix the error in the enum declaration by completing the associated value syntax.

iOS Swift

enum Result {
  case success([1] Int)
  case failure(String)
}

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Astatus

Bcode

Cerror:

Dvalue:

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the colon after the label.

Using a label without colon or just the type.

The associated value must have a label followed by a colon, like value:.

4fill in blank

hard

Fill both blanks to declare an enum case with two associated values.

iOS Swift

enum Message {
  case text([1]: String, [2]: Int)
}

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

Acontent

Blength

Csize

Dtext

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same label twice.

Omitting the colon after labels.

The enum case text has two associated values labeled content and length.

5fill in blank

hard

Fill all three blanks to create a dictionary from an enum with associated values filtering by a condition.

iOS Swift

let messages = [
  Message.text(content: "Hi", length: 2),
  Message.text(content: "Hello", length: 5),
  Message.text(content: "Hey", length: 3)
]

let filtered = messages.filter { msg in
  if case .text(let [1], let [2]) = msg {
    return [2] [3] 3
  }
  return false
}

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

Acontent

Blength

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong labels in the pattern matching.

Using the wrong comparison operator.

The code extracts content and length from each Message.text case and filters messages with length greater than 3.