Toggle navigation
MeasureThat.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
forEach(item) vs forEach(item, index, array)
(version: 0)
If we write the full prototype: arr.forEach(item, index, array) how much is the penalty?
Comparing performance of:
forEach(item) ... vs forEach(function(item, index, array) ...
Created:
7 years ago
by:
Registered User
Jump to the latest result
Script Preparation code:
var arr = ['1', '2', '3'];
Tests:
forEach(item) ...
var x; arr.forEach(function(item) { x = item * 10; });
forEach(function(item, index, array) ...
var x; arr.forEach(function(item, index, array) { // index && item not used x = item * 10; });
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
Fork
Test case name
Result
forEach(item) ...
forEach(function(item, index, array) ...
Fastest:
N/A
Slowest:
N/A
Latest run results:
No previous run results
This benchmark does not have any results yet. Be the first one
to run it!
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'd be happy to help you understand the JavaScript microbenchmarking test on MeasureThat.net. **Benchmark Definition** The benchmark tests two approaches of using the `forEach` method in JavaScript: 1. `arr.forEach(function(item) { ... })` 2. `arr.forEach(function(item, index, array) { ... })` The goal is to measure the performance penalty when using the second approach with an additional `index` parameter. **Options Compared** The two options compared are: * Using `forEach` with only one argument (i.e., `item`) * Using `forEach` with three arguments (i.e., `item`, `index`, and `array`) **Pros and Cons of Each Approach** 1. **Using `forEach` with one argument (`item`):** * Pros: + Simplifies the code + Reduces clutter by not having to declare a separate variable for the index * Cons: + Can lead to slower performance due to the overhead of calculating the index internally 2. **Using `forEach` with three arguments (`item`, `index`, and `array`):** * Pros: + Allows for more flexibility in handling the array elements * Cons: + Requires declaring a separate variable for the index, which can increase code clutter **Library Used** The `forEach` method is a built-in JavaScript function. The purpose of `forEach` is to execute a callback function on each element of an array. **Special JS Feature or Syntax** There is no special feature or syntax mentioned in this benchmark that requires special consideration. However, it's worth noting that using `forEach` with three arguments can lead to additional overhead due to the need to pass the index and array references as separate arguments. **Other Considerations** When comparing the performance of these two approaches, other factors should be considered, such as: * Array size: Smaller arrays may not show significant differences in performance. * Browser and JavaScript engine variations: Different browsers and JavaScript engines may optimize `forEach` differently. * Additional operations on the array elements: If additional operations are performed on each element (e.g., arithmetic operations), it can impact the performance difference between these two approaches. **Alternative Benchmarks** Other microbenchmarks that might be relevant to this one include: * `for` loop vs. `forEach` * Array iteration with `map`, `filter`, and `reduce` methods * JavaScript array manipulation algorithms (e.g., sorting, searching) Keep in mind that the specific benchmarking approach may depend on the use case and requirements of your project.
Related benchmarks:
Iteration through array; of vs forEach
is find faster than forEach?
Array.forEach vs Object.keys().forEach
forEach vs for of 7
Comments
Confirm delete:
Do you really want to delete benchmark?