Any and AnyObject types in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable that can hold any type of value.

Swift

var value: [1]

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AObject

BAnyObject

CAny

DNSObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using AnyObject which only holds class instances.

Using NSObject which is a specific class, not a type alias.

The Any type can hold any kind of value in Swift, including function types and optional types.

2fill in blank

medium

Complete the code to declare a variable that can hold any class instance.

Swift

var object: [1]

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

AAny

BAnyObject

CNSObject

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using Any which can hold any value, not just class instances.

Using NSObject which is a specific class, not a type alias.

The AnyObject type can hold any instance of a class in Swift.

3fill in blank

hard

Fix the error in the code by choosing the correct type for the array that holds any kind of value.

Swift

let items: [[1]] = [42, "Swift", 3.14]

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AAny

BAnyObject

CNSObject

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using AnyObject which only holds class instances, not value types like Int or Double.

The array contains values of different types, so it must be declared as an array of Any.

4fill in blank

hard

Fill both blanks to create a function that accepts any class instance and prints its description.

Swift

func describe(object: [1]) {
    print(object[2])
}

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AAnyObject

BAny

C.description

D.debugDescription

Attempts:

3 left

💡 Hint

Common Mistakes

Using Any as parameter type which accepts all types, but the function expects class instances.

Using .debugDescription which is less common for simple descriptions.

The function parameter must be AnyObject to accept class instances, and .description accesses the textual description.

5fill in blank

hard

Fill both blanks to create a function that takes Any and returns the description if it's a class instance.

Swift

func getDescription(_ value: [1]) -> String? {
    guard let obj = value as? [2] else { return nil }
    return obj.description
}

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

AAny

BAnyObject

CNSObject

DObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using AnyObject for the parameter prevents passing non-class values.

Using NSObject which is too specific and doesn't cover all classes.

Use Any for the parameter to accept any value, then cast to AnyObject to access description.