Async functions in iOS Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an async function named fetchData.

iOS Swift

func fetchData() [1] {
    // function body
}

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

Async

Bawait

Cthrows

Dasync

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'await' instead of 'async' to declare the function.

Forgetting to mark the function as async.

The async keyword declares that the function runs asynchronously.

2fill in blank

medium

Complete the code to call an async function fetchData and wait for its result.

iOS Swift

Task {
    let data = try? await [1]()
    print(data ?? "No data")
}

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

AfetchData

Bfetch

CgetData

DloadData

Attempts:

3 left

💡 Hint

Common Mistakes

Calling the function without 'await'.

Using a wrong function name.

You must call the async function by its exact name and use await to wait for its result.

3fill in blank

hard

Fix the error in the async function declaration by filling the blank.

iOS Swift

func loadData() [1] throws {
    // function body
}

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Aawait

Bsync

Casync

Dthrows async

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'await' instead of 'async' in the declaration.

Combining 'throws' and 'async' incorrectly.

The async keyword must be used to mark the function as asynchronous. It can be combined with throws but must be separate.

4fill in blank

hard

Fill both blanks to declare and call an async function correctly.

iOS Swift

func fetchUser() [1] {
    // fetch user data
}

Task {
    let user = try? await [2]()
    print(user ?? "No user")
}

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

Aasync

Bawait

CfetchUser

DloadUser

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to mark the function as async.

Calling the function without 'await'.

Using the wrong function name.

The function must be declared with async. When calling it inside a Task, use await before the function name. Here, the function name is fetchUser.

5fill in blank

hard

Fill all three blanks to create an async function that throws and call it correctly.

iOS Swift

func fetchData() [1] [2] {
    // fetch data
}

Task {
    do {
        let data = try [3] fetchData()
        print(data)
    } catch {
        print("Error")
    }
}

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

Aasync

Bthrows

Cawait

Dtry

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting 'async' or 'throws' in the function declaration.

Calling the function without 'await'.

Forgetting to use 'try' when calling a throwing function.

The function must be declared with async and throws. When calling it inside a Task, use try and await to handle errors and wait for the result.