var arr = [];for(var i=0; i < 10000; i++) { arr.push(Math.floor(Math.random() * Math.floor(10000)));}var sum = 0;arr.forEach((e, index) => {sum += arr[index];})var sum = 0;arr.forEach(e => {sum += e;})--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| foreach with index | |
| foreach without index |
| Test name | Executions per second |
|---|---|
| foreach with index | 1062.6 Ops/sec |
| foreach without index | 35073.5 Ops/sec |
Let's break down the provided benchmark and explain what's being tested.
Benchmark Definition
The benchmark is comparing two approaches to iterating over an array in JavaScript: forEach with and without indexing.
Options Compared
There are only two options being compared:
forEach without indexing: This approach uses the forEach method to iterate over the array, but it doesn't provide the index of each element as a parameter.forEach with indexing: This approach also uses the forEach method, but it provides the index of each element as a second argument ((e, index) => { ... }).Pros and Cons
forEach without indexing**: This approach is simpler to write, as it doesn't require specifying the index. However, it may be slower because the browser has to use other methods (like length`) to determine the length of the array.forEach with indexing`: This approach provides more control over the iteration process, as you can access the index and element value simultaneously. However, it requires specifying the index in the callback function, which can make the code slightly less readable.Other Considerations
The benchmark is testing how these two approaches perform on a large array of 10,000 random elements. The results will likely depend on factors like:
Library Usage
There doesn't appear to be any external libraries being used in this benchmark.
Special JS Features or Syntax
The benchmark is using a relatively modern feature: the spread operator (...) is not needed, but it's also not present. This might indicate that the test cases were written with a specific JavaScript version in mind (e.g., ES6+).
Other Alternatives
If you wanted to write your own benchmarking framework for measuring performance in JavaScript, you could use libraries like:
Benchmark.js: A popular benchmarking library for Node.js and browsers.Benchmarks.net: A simple, lightweight benchmarking tool specifically designed for web performance testing.These alternatives can provide more features, flexibility, and accurate results, but they might also require additional setup and configuration.
