javascript - Promise vs setTimeout

Question

I've observed that in the following code:

setTimeout(function(){console.log('setTimeout')});
Promise.resolve(1).then(function(){console.log('promise resolve')})

No matter how many times I execute this, the promise callback always logs before the setTimeout.

My understanding is that both callbacks are scheduled to be executed to the next tick, and I don't really understand what is going on that makes the promise always take precendence over the timeout.

Answer 1

Promise.resolve schedules a microtask and the setTimeout schedules a macrotask. And the microtasks are executed before running the next macrotask.