Why does JS code work like this?

Question

JavaScript

Good afternoon. There is a typical interview question:
What will be the result of executing the following code:

for (var i = 0; i < 10; i++) { 
  setTimeout(function () { 
    console.log(i); 
  }, 0); 
}

Will output 10 times the number 10. I completely forgot why this works? Can you remind me? Thank you.

Answer 1

https://developer.mozilla.org/en-US/docs/Web/JavaS...
Zero delay doesn't actually mean the call back will fire-off after zero milliseconds. Calling setTimeout with a delay of 0 (zero) milliseconds doesn't execute the callback function after the given interval. The execution depends on the number of waiting tasks in the queue.

Answer 2

A reference to `i` will get into the closure, and the timer function will work after the cycle has passed and i at that moment will already be 10.

Answer 3

https://www.youtube.com/watch?v=8cV4ZvHXQL4