Benchmark: lodash merge vs object.assign vs spread with access after and control

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); console.log(c)
object.assign
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = Object.assign(a, b); console.log(c)
spread
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = { ...a, ...b }; console.log(c)
control
var c = {a: 'oh', b: 'my' ,c: 'goddess' } console.log(c)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge
object.assign
spread
control

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
lodash merge	333967.1 Ops/sec
object.assign	352166.0 Ops/sec
spread	368946.1 Ops/sec
control	378170.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark compares the performance of three JavaScript methods for merging two objects:

1. `lodash.merge`
2. `Object.assign`
3. Spread operator (`...`)

Each test case has a unique implementation, and the results are reported in terms of executions per second (ExecutionsPerSecond) on a specific browser and device.

**Test Case Breakdown**

Here's a brief explanation of each test case:

1. **lodash merge**: Uses the `_.merge()` function from Lodash to merge two objects.
2. **Object.assign**: Uses the `Object.assign()` method to merge two objects.
3. **Spread operator (`...`)**: Uses the spread operator to create a new object with merged properties from two objects.
4. **Control**: A simple test case that logs an existing object without any merging.

**Comparison**

The benchmark compares the performance of these three methods in terms of executions per second (ExecutionsPerSecond). The results indicate which method is faster under specific conditions.

**Pros and Cons of each approach:**

1. **_lodash.merge**:
	* Pros: Efficiently merges objects, handles complex data structures well.
	* Cons: Requires an external library (Lodash), may have higher overhead due to the additional dependency.
2. **Object.assign**:
	* Pros: Part of the standard JavaScript library, easy to use and understand.
	* Cons: Can be slower than other methods for large objects, might not handle complex data structures well.
3. **Spread operator (`...`)**:
	* Pros: Simple, efficient, and widely supported (modern browsers and Node.js).
	* Cons: Limited support for older browsers or environments, might not work as expected with certain data types.

**Library usage**

The `lodash.merge()` function is used in the first test case. Lodash is a popular JavaScript library that provides utility functions for tasks like array manipulation, object merging, and more.

**Special JS feature/Syntax**

There are no special features or syntaxes being tested in this benchmark. The focus is on comparing the performance of three standard JavaScript methods.

**Other alternatives**

If you're interested in exploring alternative methods for merging objects, some other options include:

1. `Object.create()`: Creates a new object with properties inherited from an existing object.
2. `for...in` loop: Iterates over object properties and merges them manually.
3. Custom-built merge functions using recursion or iteration.

Keep in mind that these alternatives might have their own trade-offs in terms of performance, readability, and maintainability.

Related benchmarks:

lodash merge vs object.assign vs spread with access after and control (version: 0)

Comparing performance of: lodash merge vs object.assign vs spread vs control

Created: one year ago by: Guest

Jump to the latest result

lodash merge

object.assign

spread

control

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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