How to measure time taken by a function to execute

In this post, I will show you how to measure the execution time of any function in Javascript.
Javascript console api have two functions console.time and console.timeEnd.

  • console.time - start the timer
  • console.timeEnd - Stops a timer that was previously started by calling console.time() and prints the result to stdout:

for example,let’s suppose you have following javascript function which calculate the factorial iif give number

const fact = (number) => {
    if (number < 1) {
        return 1;
    else {
        return number * fact(number - 1);

and you want to calculate the execution time of the function.
You can wrap this function between console.time and console.timeEnd whiich will display the execution time on stdout


if execute above script you will see the following output

Factorial: 0.175ms

This approach is not reusable you can create one helper function as below

const measure = (label, fn) => {

and use like below

measure('Factorial', () => {    
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