Benchmark: Array.prototype.concat vs spread operator

HTML Preparation code:

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

Tests:

lodash merge
var a = { a: 'oh', b: 'my' } var b = { c: 'goddess' } var c = _merge(a, b)
spread operator
var a = { a: 'oh', b: 'my' } var b = { c: 'goddess' } var c = { a, ...b }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge
spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.162 Safari/537.36

Browser/OS: Chrome 65 on Mac OS X 10.12.6

View result in a separate tab

Test name	Executions per second
lodash merge	0.0 Ops/sec
spread operator	6133651.0 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and benchmark results.

**Benchmark Definition:**

The benchmark is called "Array.prototype.concat vs spread operator". The description indicates that this test compares two methods of merging arrays in JavaScript:

1. The traditional `concat()` method
2. The ES6 spread operator (`...`)

**Test Cases:**

There are two individual test cases:

### 1. Lodash merge

This test case uses the `_merge` function from the Lodash library to merge two objects, `a` and `b`.

* **Library:** Lodash is a JavaScript utility library that provides functional programming helpers, such as `merge`.
* **Purpose:** The `merge` function recursively merges values in two objects.
* **JavaScript feature or syntax used:** None specific.

The test case code is:
```javascript
var a = { a: 'oh', b: 'my' }
var b = { c: 'goddess' }
var c = _merge(a, b)
```
### 2. Spread operator

This test case uses the spread operator (`...`) to merge two objects, `a` and `b`.

* **JavaScript feature or syntax used:** ES6 spread operator (`...`)
* **Purpose:** The spread operator is used to "unpack" an array or object into individual elements.

The test case code is:
```javascript
var a = { a: 'oh', b: 'my' }
var b = { c: 'goddess' }
var c = { a, ...b }
```
**Benchmark Results:**

The latest benchmark result shows two tests:

* **Spread operator:** The test runs on Chrome 65 and executes approximately 6.13 million times per second.
* **Lodash merge:** The test also runs on Chrome 65 but fails to execute (resulting in `0` executions per second).

**Comparison:**

The spread operator approach appears to be significantly faster than using the Lodash `_merge` function.

**Pros and Cons:**

* **Spread operator:**
	+ Pros: Efficient, simple, and widely supported.
	+ Cons: Limited to merging objects or arrays into a single object/array.
* **Lodash merge:**
	+ Pros: Robust, recursive merging of objects with nested properties.
	+ Cons: Adds library dependency, potentially slower performance.

**Alternatives:**

Other alternatives for merging objects include:

* Using the `Object.assign()` method (not tested in this benchmark)
* Implementing a custom merge function
* Using other libraries like Ramda or Immutable.js (not mentioned in this benchmark)

Keep in mind that these results are specific to Chrome 65 and might vary on other browsers or environments.

Related benchmarks:

Array.prototype.concat vs spread operator (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: lodash merge vs spread operator

Created: 6 years ago by: Guest

Jump to the latest result

lodash merge

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated 6 months ago):