What is the order priority of `process.nextTick`, `Promise`, `setTimeout`, and `setImmediate`

Order priorities of process.nextTick, Promise, setTimeout and setImmediate are as follows:

1. process.nextTick: Highest priority, executed immediately after the current event loop cycle, before any other I/O events or timers.
2. Promise: Executed in the microtask queue, after the current event loop cycle, but before the next one.
3. setTimeout: Executed in the timer queue, after the current event loop cycle, with a minimum delay specified in milliseconds.
4. setImmediate: Executed in the check queue, but its order may vary based on the system and load. It generally runs in the next iteration of the event loop after I/O events.

console.log('start');
Promise.resolve().then(() => console.log('Promise'));
setTimeout(() => console.log('setTimeout'), 0);
process.nextTick(() => console.log('process.nextTick'));
setImmediate(() => console.log('setImmediate'));
console.log('end');
 
// Output:
// start
// end
// process.nextTick
// Promise
// setTimeout
// setImmediate

In summary, the order of execution is generally process.nextTick > Promise > setTimeout > setImmediate. However, keep in mind that the behavior may vary in specific situations, and the order might be influenced by factors such as system load and other concurrent operations.