How to check code execution speed?

Question

JavaScript

Hello. Recently, I have been thinking more and more about the speed of my code.
Perhaps you can tell me some utilities for this or what do you use when measuring the speed of your code?
Thanks for the replies.

Answer 1

If you are interested in a specific node, you can use performance.now :

var t0 = performance.now();
doSomething();
var t1 = performance.now();
console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");

For asynchronous tasks:

var t0 = performance.now();
var t1;
doSomething().then(result => {
  t1 = performance.now();
  console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
});