Will console.log affect to async performance?

Question

I know it's might be silly. But at least, I got this feeling many times.

Sometimes I'm trying to fix some bugs, mostly with Angular's $http request, callbacks or even with Node promise.

When things go wrong, I try to put some console.log to detect the code flow, and from that moment, (mostly) the bugs will disappear! It's not only happened to me.

So I think, somehow, console.log affect to the performance (make the program run a bit slower), and then, it makes the bugs gone!

I know I'm not the only one think this. Do you think it's possible? Or have you also meet this kind of issue before? please discuss!

Answer 1

Certainly!

This is especially noticeable when logging many items in a loop, or when logging complex objects. Calls to console.log can be time consuming, and consequently, that delay can resolve some of your race conditions.

Answer 2

JavaScript usually considered as single threaded. that why it is most likely any extra code row will effect the performance.

here is a great answer why it is not sure that it is :(

Is javascript guaranteed to be single-threaded?

Good Luck!