Why async and await are needed in Javascript - Quick Recap

Recall & Review

beginner

What problem do async and await solve in JavaScript?

They help manage asynchronous code in a way that looks and behaves like synchronous code, making it easier to read and write.

beginner

What does the async keyword do when added before a function?

It makes the function return a Promise and allows the use of await inside it.

beginner

How does await improve code readability?

It pauses the function execution until the Promise resolves, so you can write code that looks like normal sequential steps.

intermediate

Why is using callbacks sometimes problematic compared to async/await?

Callbacks can lead to nested code that is hard to read and maintain, often called 'callback hell'. async/await avoids this by flattening the code structure.

intermediate

What happens if you forget to use await before a Promise inside an async function?

The function continues without waiting for the Promise to resolve, which can cause unexpected behavior or errors.

What does the async keyword do to a function?

A Makes the function return a Promise

B Makes the function synchronous

C Blocks the entire program until it finishes

D Automatically runs the function in the background

The async keyword makes the function always return a Promise, allowing use of await inside it.

What is the main benefit of using await inside an async function?

A It pauses execution until the Promise resolves

B It makes the function run faster

C It converts synchronous code to asynchronous

D It prevents errors automatically

await pauses the function execution until the Promise resolves, making asynchronous code easier to read.

Which problem does async/await help avoid compared to callbacks?

A Memory leaks

B Syntax errors in JavaScript

C Slow internet connections

D Callback hell with deeply nested code

async/await helps avoid callback hell by flattening asynchronous code structure.

If you forget to use await before a Promise, what happens?

A The Promise resolves instantly

B The function continues without waiting for the Promise

C The program crashes immediately

D The function becomes synchronous

Without await, the function does not wait for the Promise, which can cause unexpected results.

Why is asynchronous programming important in JavaScript?

A To use more memory

B To make the code run slower

C To avoid blocking the user interface during long tasks

D To write less code

Asynchronous programming prevents blocking the UI, keeping apps responsive during long operations.

Explain why async and await are useful in JavaScript programming.

Think about how they help with waiting for tasks without freezing the program.

Describe what happens if you use an async function but forget to use await when calling a Promise inside it.

Consider how the function flow changes without waiting.