What type of object is always returned when using async in JavaScript?

What type of object is always returned when using async in JavaScript?

• A. String
• B. Promise
• C. Null
• D. Array

Answer: (B)

When using the `async` keyword in JavaScript, the function automatically returns a Promise. This feature is central to how asynchronous programming is handled in JavaScript. When you define a function as `async`, no matter what you explicitly return within that function, it will be wrapped in a Promise. For instance, if you return a value directly from an `async` function, that value becomes the resolved value of the Promise. If you throw an error within an `async` function, it results in the Promise being rejected. This behavior is fundamental to using async functions, as it allows developers to work with Promises directly when handling asynchronous operations, chaining them and using methods like `.then()` and `.catch()` to manage outcomes. This understanding is crucial when working with modern JavaScript, especially in scenarios involving web APIs, asynchronous data fetching, or any operations that take time to complete. The expected usage of Promise allows for improved readability and easier handling of asynchronous flows in code.

When using the async keyword in JavaScript, the function automatically returns a Promise. This feature is central to how asynchronous programming is handled in JavaScript. When you define a function as async, no matter what you explicitly return within that function, it will be wrapped in a Promise.

For instance, if you return a value directly from an async function, that value becomes the resolved value of the Promise. If you throw an error within an async function, it results in the Promise being rejected. This behavior is fundamental to using async functions, as it allows developers to work with Promises directly when handling asynchronous operations, chaining them and using methods like .then() and .catch() to manage outcomes.

This understanding is crucial when working with modern JavaScript, especially in scenarios involving web APIs, asynchronous data fetching, or any operations that take time to complete. The expected usage of Promise allows for improved readability and easier handling of asynchronous flows in code.