Benchmark: lodash merge vs lodash assign vs object.assign vs spread vs. native assign

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);
lodash assign
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = _.assign(a, b);
spread
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = { ...a, ...b };
assign
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = Object.assign({}, a, b);
Native assign
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = { a: a.a, b: a.b, c: b.c};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge
lodash assign
spread
assign
Native assign

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript benchmarks!

**Benchmark Overview**

The provided JSON represents a benchmark test that compares the performance of different approaches for merging or assigning objects in JavaScript.

**Test Cases and Approaches**

There are four test cases:

1. **_ (Lodash merge)**: Uses Lodash's `merge` function to combine two objects.
2. **_(Lodash assign)**: Uses Lodash's `assign` function to copy properties from one object to another.
3. **(Spread)**: Uses the spread operator (`{...}`) to create a new object by merging properties from two existing objects.
4. **Native assign**: Directly assigns properties from one object to another using `{a: a.a, b: a.b, c: b.c}`.

**Pros and Cons of Each Approach**

1. **Lodash merge**: Pros:
	* Easy to use and understand.
	* Handles cases where objects have different types (e.g., strings vs. numbers).
	* Provides a more comprehensive result compared to other methods.
Cons:
	* Requires an external library (Lodash), which may introduce additional overhead.
2. **Lodash assign**: Pros:
	* Also easy to use and understand.
	* Similar performance characteristics to `merge` since both involve copying properties.
Cons:
	* Only copies existing properties, not adding new ones or handling conflicts.
3. **Spread**: Pros:
	* Simple and concise syntax.
	* Creates a new object without modifying the original one.
Cons:
	* May not handle cases where objects have different types or conflicting properties.
4. **Native assign**: Pros:
	* Fastest execution among all methods since it avoids any additional overhead (no external libraries).
Cons:
	* Requires manual property access and handling of potential conflicts.

**Library - Lodash**

Lodash is a popular JavaScript library that provides various utility functions, including `merge` and `assign`. These functions are designed to handle common data manipulation tasks efficiently. By using these functions, developers can write concise and readable code while leveraging the expertise of the Lodash team.

**Special JS Feature or Syntax - None**

None of the test cases rely on any special JavaScript features or syntax beyond standard language support.

**Other Alternatives**

For those looking for alternatives to these methods:

* For merging objects without using an external library, consider using `Object.assign()` or implementing a custom merge function.
* For copying properties without adding new ones, consider using `Object.assign()` with the spread operator (`{...}`) or writing a custom copy function.
* If you want to avoid any additional overhead, consider using a native implementation like `{a: a.a, b: a.b, c: b.c}`, but be aware of potential conflicts and edge cases.

Overall, this benchmark test highlights the trade-offs between different approaches for merging or assigning objects in JavaScript. By understanding these pros and cons, developers can choose the most suitable method for their specific use case, taking into account factors like performance, readability, and maintainability.

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/74.0.3729.131 Safari/537.36

Browser/OS: Chrome 74 on Windows

View result in a separate tab

Test name	Executions per second
lodash merge	1402831.9 Ops/sec
lodash assign	1715951.2 Ops/sec
spread	2203882.5 Ops/sec
assign	2547050.2 Ops/sec
Native assign	893619904.0 Ops/sec

Related benchmarks:

lodash merge vs lodash assign vs object.assign vs spread vs. native assign (version: 0)

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

Created: 5 years ago by: Guest

Jump to the latest result

lodash merge

lodash assign

spread

assign

Native assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):