Benchmark: Fixed lodash merge vs object.assign vs spread

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

Fastest: N/A

Slowest: N/A

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

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Let's dive into the provided benchmark.

**Benchmark Overview**

The benchmark compares three ways to merge two objects in JavaScript:

1. Using `_.merge` from the Lodash library
2. Using `Object.assign`
3. Using the spread operator (`{ ...a, ...b }`)

**Options Comparison**

Here's a brief overview of each option:

* **Lodash Merge**: The Lodash `merge` function is used to merge two objects recursively. It takes an optional options object to customize the merging behavior.
* **Object.assign**: This method returns a new object with the properties from `a` and `b` assigned to it. It only merges own enumerable properties, not inherited ones.
* **Spread Operator**: The spread operator (`{ ...a, ...b }`) creates a new object with the properties of `a` and `b` copied into it. This method is more concise but may be slower than the other two options.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Lodash Merge**:
	+ Pros: Recursively merges objects, handles nested objects, and can customize the merging behavior with an options object.
	+ Cons: Requires including Lodash as a dependency, may be slower than `Object.assign` due to additional overhead.
* **Object.assign**:
	+ Pros: Fast, efficient, and easy to use. Only merges own enumerable properties.
	+ Cons: Does not handle nested objects or custom merging behavior out of the box.
* **Spread Operator**:
	+ Pros: Concise, readable, and can be faster than `_.merge` due to reduced overhead.
	+ Cons: May not handle all edge cases correctly, such as inherited properties or special types like `undefined`.

**Library Description**

The Lodash library is a popular utility library for JavaScript that provides a wide range of functions for tasks like array manipulation, object merging, and more. In this benchmark, the `_.merge` function is used to merge two objects recursively.

**Special JS Feature/Syntax**

There are no special JS features or syntaxes mentioned in this benchmark. The tests focus on comparing three simple ways to merge objects.

**Other Alternatives**

If you're interested in alternative approaches to merging objects, here are a few:

* Using `Object.assign` with custom merge functions (e.g., using `_.defaultsDeep` from Lodash)
* Using a library like Immer or mobx for immutable object updates
* Implementing your own recursive merge function

Keep in mind that each approach has its trade-offs and may be better suited for specific use cases.

Related benchmarks:

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

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

Created: 5 years ago by: Guest

Jump to the latest result

lodash merge

object.assign

spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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