What are the differences between process.nextTick(), setImmediate(), and setTimeout()?

  • process.nextTick() schedules a callback to be invoked in the same phase of the event loop, before any I/O operations.
  • setImmediate() schedules a callback to be executed in the next iteration of the event loop, after the current phase completes.
  • setTimeout(callback, 0) schedules a callback for execution after a minimum timeout, which can lead to delays based on the timer’s accuracy.

Example:

console.log('Start');

process.nextTick(() => console.log('Next Tick')); // Executes first
setImmediate(() => console.log('Immediate')); // Executes second
setTimeout(() => console.log('Timeout'), 0); // Executes last

console.log('End');