async let and Concurrent Child Tasks
Running independent async work concurrently with async let bindings.
Welcome
`async let` runs multiple async operations concurrently — all start immediately, and `await` waits for their results when needed.
Sequential vs Concurrent
```swift
// Sequential — slow:
let a = try await fetchA()
let b = try await fetchB()
// Concurrent with async let — fast:
async let a = fetchA()
async let b = fetchB()
let (resultA, resultB) = try await (a, b)
```
All lessons in this course
- async/await Syntax and Calling Async Functions
- Task and Task Cancellation
- async let and Concurrent Child Tasks
- Actors: Protecting Shared Mutable State