Benchmark: lodash merge vs lodash assign vs object.assign vs spread - 2 Levels

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js'></script>

Tests:

lodash merge
var a = { a: 'oh', b: 'my', d: { x: 1 } }; var b = { c: 'goddess', d: { x: 2, y: 99 } }; var c = _.merge(a, b);
lodash assign
var a = { a: 'oh', b: 'my', d: { x: 1 } }; var b = { c: 'goddess', d: { x: 2, y: 99 } }; var c = _.assign(a, b);
spread
var a = { a: 'oh', b: 'my', d: { x: 1 } }; var b = { c: 'goddess', d: { x: 2, y: 99 } }; var c = { ...a, ...b };
assign
var a = { a: 'oh', b: 'my', d: { x: 1 } }; var b = { c: 'goddess', d: { x: 2, y: 99 } }; var c = Object.assign({}, a, b);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge
lodash assign
spread
assign

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'll break down the benchmark and its individual test cases.

**Overview**

The provided JSON represents a JavaScript microbenchmark created on MeasureThat.net, which compares the performance of four different methods to merge or assign objects: `lodash.merge`, `lodash.assign`, object spread syntax (`...`), and `Object.assign()`.

**Options being compared**

1. **Lodash Merge**: `_.merge()`, a function from the Lodash library that merges two or more objects into one, overwriting properties from source objects.
2. **Lodash Assign**: `_.assign()`, a function from the Lodash library that creates a new object by copying all own enumerable properties from one or more source objects.
3. **Object Spread Syntax**: The spread operator (`...`) used to merge two or more objects into one, creating a new object with the combined properties.
4. **Object Assign**: `Object.assign()`, a method on the Object prototype that creates a new object by copying all enumerable own properties from one or more source objects.

**Pros and Cons**

1. **Lodash Merge**: Pros:
	* Can merge multiple objects into one, handling complex data structures.
	* Has some built-in logic for handling differences between source objects.
Cons:
	* Requires the Lodash library to be included in the test environment.
2. **Lodash Assign**: Pros:
	* Fast and lightweight, making it suitable for high-performance applications.
	* Can merge multiple objects into one, but with less control than `_.merge()`.
Cons:
	* Only merges two objects at a time; not suitable for complex data structures.
3. **Object Spread Syntax**: Pros:
	* Very concise and readable syntax.
	* Fast and efficient, as it creates a new object without modifying the original.
Cons:
	* Limited to merging two objects at a time.
4. **Object Assign**: Pros:
	* Fast and lightweight, making it suitable for high-performance applications.
	* Can be used with multiple source objects in a single call.
Cons:
	* Does not support all properties from source objects (e.g., `undefined` or functions).

**Library: Lodash**

Lodash is a popular JavaScript library that provides various utility functions, including the `merge()` and `assign()` methods. It helps simplify common operations, making code more concise and readable.

**Special JS feature: ES6 Spread Syntax**

The object spread syntax (`...`) is a relatively new feature introduced in ECMAScript 2015 (ES6). It allows you to create a new object by copying all own enumerable properties from one or more source objects, without modifying the original. This syntax is concise and readable but limited to merging two objects at a time.

**Alternatives**

If you're interested in exploring alternative methods for merging objects, consider:

1. **Object.assign()**: Similar to `_.assign()` (Lodash), but part of the built-in Object prototype.
2. **JSON Merge Patch**: A lightweight library that provides a simple way to merge two objects while handling differences between source objects.
3. **Immutable.js**: A library that provides immutable data structures, which can be used for merging and updating data.

In summary, each method has its strengths and weaknesses, and the choice ultimately depends on your specific use case, performance requirements, and personal preference.

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/75.0.3770.18 Safari/537.36 Edg/75.0.139.4

Browser/OS: Chrome 75 on Windows

View result in a separate tab

Test name	Executions per second
lodash merge	575919.9 Ops/sec
lodash assign	2232430.5 Ops/sec
spread	2756723.5 Ops/sec
assign	3781567.2 Ops/sec

Related benchmarks:

lodash merge vs lodash assign vs object.assign vs spread - 2 Levels (version: 0)

Comparing performance of: lodash merge vs lodash assign vs spread vs assign

Created: 5 years ago by: Guest

Jump to the latest result

lodash merge

lodash assign

spread

assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):