Async/await and Futures in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Future in Flutter?

A Future represents a value that will be available later, like waiting for a friend to arrive. It helps handle tasks that take time, such as loading data from the internet.

beginner

What does the async keyword do in a function?

It marks the function as asynchronous, allowing you to use await inside it to pause execution until a Future completes, making code easier to read.

beginner

How does the await keyword work?

It pauses the function execution until the Future finishes and returns its result, like waiting for a text message before continuing.

intermediate

Why use async/await instead of callbacks?

Async/await makes code look simple and linear, avoiding nested callbacks that can be confusing, just like following a clear recipe step-by-step.

intermediate

What happens if a Future throws an error and you use async/await?

You can catch the error using try-catch blocks around the await call, helping you handle problems gracefully without crashing the app.

What type does an async function return in Flutter?

A String

B void

C Future

D int

Async functions always return a Future, even if you return a simple value inside.

Which keyword pauses execution until a Future completes?

A async

B then

C yield

D await

The await keyword pauses the function until the Future finishes.

How do you handle errors in async/await code?

A Using try-catch blocks

B Using if-else statements

C Using switch-case

D Errors cannot be handled

Try-catch blocks let you catch and handle errors from awaited Futures.

What does a Future represent?

A A value available later

B A value available now

C A synchronous function

D A UI widget

A Future represents a value that will be ready in the future.

Which of these is a benefit of async/await?

A Makes code harder to read

B Avoids nested callbacks

C Blocks the UI thread

D Removes the need for Futures

Async/await helps avoid nested callbacks, making code clearer.

Explain how async and await work together in Flutter to handle long tasks.

Think about waiting for a friend before continuing your plan.

Describe how you would handle errors when using async/await in Flutter.

Imagine catching a problem before it breaks your app.