Why generics provide type safety in Swift - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a generic function that returns the same type it receives.

Swift

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

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

Aelement

Bitem

Cinput

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using a parameter name that is not declared, causing a compile error.

The parameter name value matches the return type T and is used inside the function.

2fill in blank

medium

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

Swift

struct Box<[1]> {
    var content: T
}

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

AV

BU

CT

DX

Attempts:

3 left

💡 Hint

Common Mistakes

Using a generic parameter name that does not match the property type.

The generic type parameter T is used to define the type of the property content.

3fill in blank

hard

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

Swift

func swapValues<[1]>(_ a: inout T, _ b: inout T) {
    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 a generic parameter that does not match the function parameters.

The generic type parameter T must be declared to match the parameter types.

4fill in blank

hard

Fill both blanks to create a generic function that compares two values of the same type.

Swift

func areEqual<[1]>(_ a: [2], _ b: T) -> Bool {
    return a == b
}

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

AT

BU

Attempts:

3 left

💡 Hint

Common Mistakes

Using different generic type parameters for parameters that must be the same type.

The generic type parameter T is declared and used as the type of both parameters to ensure they are the same type.

5fill in blank

hard

Fill all three blanks to create a generic function that returns the first element of an array of any type.

Swift

func firstElement<[1]>(of array: [[2]]) -> [3]? {
    return array.first
}

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

AT

DU

Attempts:

3 left

💡 Hint

Common Mistakes

Using different generic type parameters for the array and return type.

The generic type parameter T is declared and used consistently for the array element type and the return type.