Benchmark: test loop - MeasureThat.net

Script Preparation code:

var replacementTags = ['Hola', 'A', 'B', 'Adios'];
var customLocalTags = [];

Tests:

forEach
replacementTags.forEach((tag) => { customTag = { value: tag, name: tag }; customLocalTags.push(customTag); });
map
customLocalTags = replacementTags.map((tag) => { return { value: tag, name: tag }; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.106 Safari/537.36

Browser/OS: Chrome 80 on Linux

View result in a separate tab

Test name	Executions per second
forEach	347113.1 Ops/sec
map	3459118.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is defined by two test cases, which are actually examples of JavaScript methods: `map` and `forEach`. The benchmark itself is not explicitly defined, but we can infer its purpose from the code.

In the first test case, `map`, a function is created to transform each element in an array. In this specific example, it returns an object with two properties: `value` and `name`, where both are set to the current element of the array (`tag`). The transformed elements are then pushed onto another array, `customLocalTags`.

In the second test case, `forEach`, a similar transformation is applied to each element in the `replacementTags` array. However, instead of creating an object and pushing it to an array, it assigns the result directly to a variable named `customTag`. This assignment operation might be more relevant to measuring execution speed.

**Options Compared**

The two test cases are compared by executing them on the same input data: the `replacementTags` array. The difference lies in how the transformation is applied:

1. **map**: Creates an array of transformed objects and pushes them onto another array.
2. **forEach**: Assigns the result directly to a variable, without creating an array.

**Pros and Cons**

**map**:

Pros:

* More efficient, as it only creates one array with the transformed elements.
* Avoids unnecessary memory allocation and copying.

Cons:

* Requires extra memory for the `customLocalTags` array, which might not be significant but still adds overhead.
* The assignment operation itself is likely to be slower due to JavaScript's garbage collection requirements.

**forEach**:

Pros:

* Does not require creating an additional array, reducing memory allocation and copying overhead.
* Eliminates the need for manual iteration using loops.

Cons:

* Requires more computational resources, as each element is processed individually, potentially leading to slower performance.
* May incur higher memory pressure due to the assignment operation.

**Library Used**

There is no explicit library used in these test cases. The `map` and `forEach` methods are built-in JavaScript functions.

**Special JS Feature or Syntax**

The `map` method uses a modern JavaScript feature called "arrow functions" (`=>`) for conciseness, which is part of ECMAScript 2015 (ES6). It's not necessary to have deep knowledge of this feature to understand the code. However, being aware of its existence can help with benchmarking and performance analysis.

**Other Alternatives**

To measure similar performance characteristics, you might consider using other JavaScript methods or techniques, such as:

* Using a loop instead of `forEach` for manual iteration.
* Creating an array with the transformed elements before pushing them onto another array (to avoid extra memory allocation).
* Comparing the execution speed of hand-crafted loops versus built-in methods like `map` and `forEach`.

Keep in mind that the choice of alternative implementation will depend on your specific requirements, such as performance optimization or simplifying code.

Related benchmarks:

test loop (version: 0)

Comparing performance of: forEach vs map

Created: 4 years ago by: Guest

Jump to the latest result

forEach

map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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