How do you run async operations in parallel in JavaScript?
With promises: Promise.all([fetchA(), fetchB(), fetchC()]).then(...). With async/await: const [a, b, c] = await Promise.all([fetchA(), fetchB(), fetchC()]). Both run the operations in parallel and wait for all to complete.
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More FAQs in Callback vs Promise vs Async/Await in JavaScript
Callbacks are the original (deep nesting, manual errors). Promises flatten chaining with .then and .catch. Async/await makes async code look synchronous with try/catch. Async/await is built on promises; they can be mixed.
Use async/await for most modern code. It is more readable, easier to debug (better stack traces), and uses try/catch for errors. Use promises directly when you need Promise.all for parallel or complex chaining.
Yes. async/await is syntactic sugar over promises. An async function always returns a promise. await pauses until the promise resolves. You can mix await with Promise.all and other promise methods.
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