What are better alternatives to setTimeout(cb, 0) in JavaScript?
queueMicrotask(fn) runs fn as a microtask (before the next macrotask). requestAnimationFrame(fn) runs fn before the next paint (best for visual updates). requestIdleCallback(fn) runs fn when the browser is idle (best for low-priority work).
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More FAQs in setTimeout with Zero Delay Explained
No. The callback goes to the macrotask queue. The event loop runs it only after the call stack is empty and all microtasks are done. So it runs after the current synchronous code, not immediately.
Because promise callbacks go to the microtask queue, which the event loop drains completely before touching the macrotask queue where setTimeout callbacks live. Microtasks always run before macrotasks, regardless of delay.
Deferring work to keep the UI responsive, breaking long tasks into chunks (so the browser can render between chunks), and allowing the browser to paint a UI update before a heavy task blocks the thread.
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