Benchmark: Test concat vs flatter in loop etc

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.min.js"></script>

Script Preparation code:

var arr = [];
for (var i = 0; i < 10000; i++) {
	arr.push(() => [i]);
};

Tests:

Map
let nodesFoundByClassName = _.flatten(_.map(arr, (el) => el()));
Concat
let nodesFoundByClassName = []; for (let i = 0, len = arr.length; i < len; i++) nodesFoundByClassName = nodesFoundByClassName.concat(arr[i]());
Chain
let nodesFoundByClassName = _.chain(arr).map(arr, (el) => el()).flatten().value();
Push with end flatten
let nodesFoundByClassName = []; for (let i = 0, len = arr.length; i < len; i++) nodesFoundByClassName.push(arr[i]()); nodesFoundByClassName = _.flatten(nodesFoundByClassName);
Index assign with end flatten
var i = -1; var length = arr.length; var nodesFoundByClassName = Array(length); while (++i < length) { nodesFoundByClassName[i] = arr[i](); } nodesFoundByClassName = _.flatten(nodesFoundByClassName);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map
Concat
Chain
Push with end flatten
Index assign with end flatten

Fastest: N/A

Slowest: N/A

Latest run results:

No previous 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 benchmark JSON and explain what is being tested, compared options, pros and cons, and other considerations.

**Benchmark Definition**

The benchmark measures the performance of different approaches to flatten an array of functions in JavaScript. The array is created using the `push` method, which adds elements to the end of the array. The benchmark checks how fast each approach can flatten this array of functions into a single array.

**Options Compared**

1. **Map**: Uses the `map()` method to apply the function to each element in the array and returns a new array with the results.
2. **Concat**: Uses the `concat()` method to concatenate an empty array with the result of calling each function in the original array.
3. **Chain**: Uses Lodash's `chain()` method to create a fluent chain of operations, followed by `map()`, `flatten()`, and finally `value()`.
4. **Push with end flatten**: Creates a new array using the `push()` method to add functions to it, then uses Lodash's `flatten()` method to flatten the resulting array.
5. **Index assign with end flatten**: Similar to `Push with end flatten`, but uses an indexed assignment approach.

**Pros and Cons**

1. **Map**: Pros: simple, efficient, and concise. Cons: may not be optimized for large arrays or complex functions.
2. **Concat**: Pros: easy to understand, works well for small arrays. Cons: slower than `map` due to the overhead of concatenation.
3. **Chain**: Pros: provides a fluent API, can be useful for method chaining. Cons: slower due to Lodash's overhead and the need to create an intermediate array.
4. **Push with end flatten**: Pros: avoids creating unnecessary arrays, efficient for large inputs. Cons: more verbose than other approaches.
5. **Index assign with end flatten**: Similar pros and cons as `Push with end flatten`.

**Library Used**

Lodash is used in options 3 (`Chain`) and 4 (`Push with end flatten`).

**Special JS Feature/Syntax**

None mentioned.

**Other Considerations**

* The benchmark assumes that the functions in the array are independent and can be executed concurrently.
* The `push` method's performance impact is significant due to its overhead.
* Using an indexed assignment approach (`Index assign with end flatten`) may improve performance by avoiding the need for concatenation.

**Alternatives**

Other approaches to flattening arrays of functions could include:

* Using `reduce()` or `forEach()`
* Implementing a custom loop-based solution
* Utilizing libraries like Fastify or Koa.js, which provide optimized array manipulation APIs

However, these alternatives are not included in the provided benchmark JSON.

Related benchmarks:

Test concat vs flatter in loop etc (version: 0)

Comparing performance of: Map vs Concat vs Chain vs Push with end flatten vs Index assign with end flatten

Created: 8 years ago by: Guest

Jump to the latest result

Map

Concat

Chain

Push with end flatten

Index assign with end flatten

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):