how to track execution time in javascript

There are multiple ways to track execution time in JavaScript. One approach is to use the console object to output the time before and after a piece of code, and calculate the difference. Here's an example:

index.tsx
// start timer
console.time('myFunction');

// code to be timed
myFunction();

// stop timer and output elapsed time
console.timeEnd('myFunction');
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Another approach is to use the performance object, which provides a more precise way to measure time:

index.tsx
// start timer
const t0 = performance.now();

// code to be timed
myFunction();

// stop timer and output elapsed time
const t1 = performance.now();
console.log(`Elapsed time: ${t1 - t0} milliseconds.`);
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Finally, there are also benchmarking libraries like Benchmark.js that provide more advanced features for performance testing.