Why enums are powerful in Swift - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an enum named Direction.

Swift

enum [1] {
    case north
    case south
    case east
    case west
}

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AMove

Bdirection

CDirections

DDirection

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or plural names for enum types.

The enum name should be Direction to follow Swift naming conventions.

2fill in blank

medium

Complete the code to create a variable with the enum value east.

Swift

var currentDirection: Direction = Direction.[1]

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Aeast

BEast

CNorth

Dwest

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase 'East' when the enum case is lowercase 'east'.

Enum cases in Swift start with lowercase by convention. The case is east as per the enum declaration.

3fill in blank

hard

Fix the error in the switch statement to handle all enum cases.

Swift

switch currentDirection {
case .north:
    print("Going north")
case .south:
    print("Going south")
case [1]:
    print("Going east")
default:
    print("Unknown direction")
}

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A.west

B.east

Ceast

Dwest

Attempts:

3 left

💡 Hint

Common Mistakes

Using case without dot notation or missing cases.

The missing case is .east to cover the east direction in the switch.

4fill in blank

hard

Fill both blanks to create an enum with associated values and assign it.

Swift

enum Barcode {
    case upc(Int, Int, Int, Int)
    case qrCode(String)
}

var productBarcode = Barcode.[1]([2])

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AqrCode

B"ABCDEFGHIJKLMNOP"

Cupc

D12345, 67890, 1112, 1314

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up case names or providing wrong value types.

The enum case upc takes four integer values as associated values.

5fill in blank

hard

Fill all three blanks to create a recursive enum and use it.

Swift

indirect enum ArithmeticExpression {
    case number(Int)
    case addition([1], [2])
    case multiplication([3], ArithmeticExpression)
}

let five = ArithmeticExpression.number(5)

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AArithmeticExpression

BInt

DNumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using primitive types instead of the enum type for recursion.

The recursive enum uses ArithmeticExpression as the type for its associated values.