Benchmark: concat vs lodash.concat vs flat

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Tests:

Array.prototype.concat
var params = [ "hello", "hello", "sname" ]; var other = [].concat([ "red", "wine" ],params);
Lodash concat
var params = [ "hello", "hello", "sname" ]; var other = _.concat([ "red", "wine" ], params);
Flat
var params = [ "hello", "hello", "sname" ]; var other = [[ "red", "wine" ], params].flat();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
Lodash concat
Flat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36

Browser/OS: Chrome 77 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	6619601.0 Ops/sec
Lodash concat	2291086.5 Ops/sec
Flat	1131274.8 Ops/sec

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

LLMs can make mistakes. Check important info.

**What is being tested?**

MeasureThat.net is testing the performance of three different approaches to concatenate an array with another array:

1. `Array.prototype.concat()`: This is a built-in method in JavaScript that concatenates two arrays and returns a new array.
2. `_.concat()` from Lodash: Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks such as string manipulation, array manipulation, and more.
3. `.flat()` on an array with two elements: This method was introduced in ECMAScript 2019 (ES2020) and flattens an array to a one-dimensional array.

**Options compared**

The three options are being compared in terms of their execution time. The benchmark measures how many executions per second each option can handle.

**Pros and Cons of each approach:**

1. `Array.prototype.concat()`:
	* Pros: Built-in method, widely supported across browsers.
	* Cons: May be slower than other methods due to its implementation.
2. `_.concat()` from Lodash:
	* Pros: Provides a convenient way to concatenate arrays with a simple function call. Lodash is widely used and well-maintained.
	* Cons: Adds an extra dependency (Lodash) to the project, which may not be desirable for smaller projects or projects that require no additional dependencies.
3. `.flat()` on an array with two elements:
	* Pros: Native method introduced in ES2020, highly optimized by browsers.
	* Cons: May not be supported in older browsers.

**Library and its purpose**

Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks such as string manipulation, array manipulation, and more. In this benchmark, Lodash's `concat` function is being used to concatenate an array with another array.

**Special JS feature or syntax**

The `.flat()` method introduced in ES2020 (ES2019) is the special JavaScript feature being tested here. It was not widely supported until recent browsers like Chrome 77 and later versions started supporting it.

**Other alternatives**

In addition to these three options, there may be other ways to concatenate arrays in JavaScript, such as using `Array.prototype.push()` followed by a single call to `Array.prototype.concat()`, or using `Array.from()` to create a new array from an existing array and another array. However, these approaches are not being tested in this benchmark.

**Benchmark preparation code**

The script preparation code is:

```javascript
var params = [ "hello", "hello", "sname" ];
```

And the HTML preparation code is:

```html
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
```

Note that the `params` variable is an array with three elements, which will be used to test the concatenation performance of the three options.

Related benchmarks:

concat vs lodash.concat vs flat (version: 0)

Comparing performance of: Array.prototype.concat vs Lodash concat vs Flat

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.concat

Lodash concat

Flat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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