Async programming, a core concept in JavaScript, focuses on handling asynchronous operations – operations that don't immediately return a result. It's crucial for building responsive and scalable applications.
- Promises: An object that represents the eventual completion (or failure) of an asynchronous operation. They encapsulate the result and allow for handling failures gracefully. - Callbacks: A set of functions that are executed after a certain point in an asynchronous operation. Can be problematic in larger codebases. - Promises.then() & Promise.reject(): Methods that allow for chaining and error handling.
Consider fetching data from an API using `fetch`. The response is an array of promises. You'll need to handle errors and `then()` callbacks to process the data.
```javascript async function fetchData() { try { const response = await fetch('https://example.com/api/data'); if (!response.ok) { throw new Error('Network error'); } const data = await response.json(); console.log(data); } catch (error) { console.error(error); } } fetchData();
Async programming reduces callback hell, simplifies code, and improves scalability. It helps write cleaner, more maintainable code.