Task groups for parallel execution in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a task group in Swift.

Swift

try await [1](of: Int.self) { group in
    // parallel tasks here
}

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

Agroup

BwithGroup

CwithTaskGroup

DtaskGroup

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'group' or 'taskGroup' which are not valid Swift concurrency methods.

Confusing 'withGroup' with the correct 'withTaskGroup'.

The correct method to start a task group in Swift concurrency is 'withTaskGroup'.

2fill in blank

medium

Complete the code to add a child task inside a task group.

Swift

try await withTaskGroup(of: Int.self) { group in
    group.[1] {
        return 42
    }
}

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Aadd

BaddTask

Cspawn

Dasync

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'async' which is a keyword, not a method here.

Using 'spawn' which is not a Swift concurrency method.

The method to add a child task to a task group is 'addTask'.

3fill in blank

hard

Fix the error in the code to await results from all child tasks in the group.

Swift

try await withTaskGroup(of: Int.self) { group in
    group.addTask {
        return 10
    }
    var sum = 0
    for await result in group.[1] {
        let value = try result.get()
        sum += value
    }
    return sum
}

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Aresults

Bvalues

Call

Dawait

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'values' which is not a property of TaskGroup.

Using 'await' as a property which is a keyword.

The correct property to iterate over all child task results is 'results'.

4fill in blank

hard

Fill both blanks to create a task group that returns the first completed child task result.

Swift

try await withTaskGroup(of: Int.self) { group in
    group.[1] {
        return 5
    }
    group.[2] {
        return 10
    }
    for await result in group.results {
        return try result.get()
    }
}

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Aadd

Bspawn

CaddTask

Dasync

Attempts:

3 left

💡 Hint

Common Mistakes

Using different methods for adding tasks.

Using 'spawn' or 'async' which are invalid here.

Both child tasks are added using 'addTask' method to the task group.

5fill in blank

hard

Fill all three blanks to create a task group that sums only even results from child tasks.

Swift

try await withTaskGroup(of: Int.self) { group in
    group.[1] {
        return 3
    }
    group.[2] {
        return 4
    }
    var total = 0
    for await result in group.[3] {
        let number = try result.get()
        if number % 2 == 0 {
            total += number
        }
    }
    return total
}

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

AaddTask

Badd

Cresults

Dvalues

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'add' instead of 'addTask' to add child tasks.

Using 'values' instead of 'results' to iterate results.

Child tasks are added with 'addTask' and results are iterated using 'results'.