Benchmark: Nj9ZJ^FuK4AJ#wKEww

Script Preparation code:

const data = Array.from(Array(1000).keys());
var map = new Map(data.map((o) => [o, o]));
var array = [...data];

Tests:

iterate on map with values() and filter
const filtered = []; for (const o of map.values()) { if (o%2 === 0) filtered.push(o); }
iterate on map with forEach() and filter
const filtered = []; map.forEach(o => { if (o%2 === 0) filtered.push(o) });
iterate on array and filter
const filtered = array.filter(o => o % 2 === 0);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
iterate on map with values() and filter
iterate on map with forEach() and filter
iterate on array and filter

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmark in question involves measuring the performance of three different approaches for filtering an array or map.

**Benchmark Definition JSON**

The benchmark definition JSON provides the following information:

*   "Name": A unique identifier for the benchmark.
*   "Description": An optional description of the benchmark, which is empty in this case.
*   "Script Preparation Code": A JavaScript code snippet that prepares the data and variables used by the benchmark. In this case, it creates an array and a map from 0 to 999 using `Array.from` and `Map`.
*   "Html Preparation Code": An optional HTML code snippet for preparing the HTML environment for the benchmark, which is empty in this case.

**Test Cases**

The test cases are defined as an array of objects, each representing a single test. The test case definition includes:

*   "Benchmark Definition": A JavaScript code snippet that defines the specific operation to be measured.
*   "Test Name": A unique identifier for the test case.

There are three test cases:

1.  "iterate on map with values() and filter":
    *   Uses the `values()` method of the Map object to iterate over its entries, and filters out odd numbers using an array method (`push`).
2.  "iterate on map with forEach() and filter":
    *   Uses the `forEach()` method of the Map object to iterate over its entries, and filters out odd numbers using an array method (`push`).
3.  "iterate on array and filter":
    *   Directly uses the `filter()` method of the Array object to filter out odd numbers.

**Comparison**

The three test cases compare different approaches for filtering arrays or maps:

*   Iterating over a Map object using `values()`, then filtering with an array method (`push`).
*   Iterating over a Map object using `forEach()`, then filtering with an array method (`push`).
*   Directly using the `filter()` method of the Array object.

**Pros and Cons**

Here's a brief analysis of each approach:

1.  **Iterate over Map using values(), filter**: This approach is more verbose but provides better control over iteration order (stable). However, it may not be as efficient due to the extra array method call.
2.  **Iterate over Map using forEach(), filter**: This approach uses a callback function for filtering, which can lead to potential issues with scope and closure management. However, it's often more concise than using `values()` and an additional array method.
3.  **Directly use filter() on Array object**: This approach is likely the most efficient as it only involves a single method call.

In terms of performance, the `filter()` method is generally the fastest option. The `forEach()` method with filtering can be slower due to the overhead of iterating over each element using a callback function. Iterating over a Map object using `values()` and an additional array method can be slower as well, but the difference is likely minimal.

**Alternative Approaches**

Other approaches to filter arrays or maps include:

*   Using `map()` with a callback function (e.g., `map(o => o % 2 === 0)`).
*   Using `reduce()` with an accumulator and callback function.
*   Using specialized libraries like Lodash (`_.filter()`) or Ramda (`R.filter()`).

Keep in mind that each approach has its own trade-offs between conciseness, readability, and performance.

**Special JavaScript Features or Syntax**

This benchmark does not use any special JavaScript features or syntax beyond the standard language.

Related benchmarks:

Nj9ZJ^FuK4AJ#wKEww (version: 0)

Comparing performance of: iterate on map with values() and filter vs iterate on map with forEach() and filter vs iterate on array and filter

Created: 4 years ago by: Guest

Jump to the latest result

iterate on map with values() and filter

iterate on map with forEach() and filter

iterate on array and filter

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):