hardDSA

What is `process.nextTick()` and `setImmediate()` and when to use them?

Q: What is `process.nextTick()` and `setImmediate()` and when to use them?

**TL;DR.** Both defer work, but at very different times. process.nextTick(cb) runs **before the event loop continues** — right after the current operation, ahead of Promises and any phase. setImmediate(cb) runs in the **check** phase, *after* the current poll phase completes. Rule of thumb: setImmediate for "run after I/O", nextTick sparingly for "run before anything else". current op nextTick queue <text class='d-sub' x='242' y='64' te

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Advanced event loop concepts; crucial for controlling execution order.

event loopschedulingasynchronousperformance

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Ordering of the two

setImmediate(() => console.log('3 immediate'));     // check phase
Promise.resolve().then(() => console.log('2 promise')); // microtask
process.nextTick(() => console.log('1 nextTick'));       // before all

// Output: 1 nextTick, 2 promise, 3 immediate

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