Generic type declaration in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a generic function that returns the input value.

Swift

func identity<[1]>(value: [1]) -> [1] {
    return value
}

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

AX

BU

CV

DT

Attempts:

3 left

💡 Hint

Common Mistakes

Using different generic type names in the function signature.

Forgetting to declare the generic type in angle brackets.

The generic type placeholder is usually named T by convention. It allows the function to accept and return any type.

2fill in blank

medium

Complete the code to declare a generic struct with a property of the generic type.

Swift

struct Container<[1]> {
    var item: [1]
}

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

AElement

BItem

CT

DValue

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the generic type parameter and the property type.

Not using angle brackets to declare the generic type.

The generic type placeholder T is commonly used in Swift to represent a generic type parameter.

3fill in blank

hard

Fix the error in the generic function declaration by completing the missing generic type placeholder.

Swift

func swapValues<[1]>(a: inout [1], b: inout [1]) {
    let temp = a
    a = b
    b = temp
}

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

AT

BU

CV

DW

Attempts:

3 left

💡 Hint

Common Mistakes

Using different generic type names for the parameters.

Omitting the generic type declaration.

The generic type placeholder T is used consistently to allow swapping values of any type.

4fill in blank

hard

Fill both blanks to declare a generic class with a method that returns the stored value.

Swift

class Box<[1]> {
    var value: [1]
    init(value: [2]) {
        self.value = value
    }
    func getValue() -> [1] {
        return value
    }
}

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

AT

BU

DV

Attempts:

3 left

💡 Hint

Common Mistakes

Using different generic type names in the class and initializer.

Forgetting to declare the generic type.

The generic type T is used consistently for the class and initializer parameter.

5fill in blank

hard

Fill all three blanks to declare a generic function that swaps two values of any type.

Swift

func swapTwoValues<[1]>(a: inout [2], b: inout [3]) {
    let temp = a
    a = b
    b = temp
}

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

AT

DU

Attempts:

3 left

💡 Hint

Common Mistakes

Using different generic type names for the parameters.

Omitting the generic type declaration.

The generic type T is used consistently to allow swapping values of the same type.