Benchmark: Map and Filter vs forEach vs for

Script Preparation code:

var jobIds = [1, 2, 3, 4, 5]
var jobs = {
  1: { status: 2 },
  2: { status: 1 },
  3: { status: 3 },
  4: { status: 2 },
  5: { status: 3 }
}

Tests:

map and filter
var activeJobs = jobIds.map(id => jobs[id]).filter(job => job.status !== 3)
forEach
var activeJobs = [] jobIds.forEach(id => { var job = jobs[id] if (job.status !== 3) activeJobs.push(job) })
for
var activeJobs = [] for (i = 0; i < jobIds.length; i++) { var job = jobIds[i] if (job.status !== 3) activeJobs.push(job) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map and filter
forEach
for

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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Let's break down the provided JSON to understand what is being tested and compare different approaches.

**Benchmark Definition**

The benchmark is designed to test the performance of three different approaches for filtering an array of objects: `map` and `filter`, `forEach`, and a traditional `for` loop.

The script preparation code defines two arrays, `jobIds` and `jobs`, which are used as input data. The `jobIds` array contains IDs that correspond to objects in the `jobs` object. Each object in `jobs` has a `status` property.

**Individual Test Cases**

There are three test cases:

1. **map and filter**: This test case uses the `map` function to transform each element of `jobIds` into its corresponding value in `jobs`, and then filters out any elements with a status of 3 using the `filter` function.
2. **forEach**: This test case uses the `forEach` function to iterate over each ID in `jobIds`, retrieves the corresponding object from `jobs`, and pushes it to an array if its status is not 3.
3. **for**: This test case uses a traditional `for` loop to iterate over each element of `jobIds`, retrieves the corresponding object from `jobs`, and pushes it to an array if its status is not 3.

**Libraries Used**

There are no external libraries used in this benchmark, except for built-in JavaScript functions like `map`, `filter`, `forEach`, and traditional loops.

**Special JS Features or Syntax**

None of the test cases use any special JavaScript features or syntax beyond what's considered standard. However, it's worth noting that modern browsers may optimize certain methods (e.g., `for` loop) due to their specificity in creating a loop context.

**Pros and Cons of Different Approaches**

Here's a brief overview of each approach:

* **map and filter**: This approach is concise and expressive, but it can be less performant than other approaches because it creates an intermediate array with the transformed data.
	+ Pros: Easy to read and maintain, avoids manual iteration.
	+ Cons: Creates an additional array, may not be optimized for performance.
* **forEach**: This approach uses a more traditional loop structure, which can be slower due to the overhead of function calls.
	+ Pros: More control over the loop body, no need to create intermediate arrays.
	+ Cons: May require more manual bookkeeping (e.g., managing the `activeJobs` array).
* **for**: This approach is likely optimized for performance by modern browsers, but it requires manual iteration and may be harder to read than other approaches.
	+ Pros: High performance, low memory usage.
	+ Cons: More verbose, requires manual loop maintenance.

**Other Alternatives**

Some alternative approaches that could be tested in this benchmark include:

* Using `reduce()` instead of `map` and `filter`
* Using a combination of `map`, `filter`, and array methods (e.g., `every()`)
* Using a library like Lodash for filtering and transformation
* Using Web Workers or parallel processing to improve performance

However, these alternatives might not be as straightforward or representative of common use cases, so they may not be the best choices for this specific benchmark.

Related benchmarks:

Map and Filter vs forEach vs for (version: 0)

Comparing performance of: map and filter vs forEach vs for

Created: 5 years ago by: Guest

Jump to the latest result

map and filter

forEach

for

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):