Benchmark: lodash merge vs object.assign vs spread v2

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

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.4 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 16 on iOS 16.4

View result in a separate tab

Test name	Executions per second
lodash merge	2068715.2 Ops/sec
object.assign	4687200.0 Ops/sec
spread	8199140.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and explore what's being tested in MeasureThat.net.

The provided benchmark involves three approaches to merge two objects:

1.  **Lodash `merge` method**: This approach uses the Lodash library, which is a popular utility library for functional programming tasks.
2.  **Object.assign() method**: This built-in JavaScript method is used to create a new object by copying all enumerable own properties from one or more source objects onto a target object.
3.  **Spread operator (`...`)**: This syntax allows you to create a new object with the properties of an existing object and add new key-value pairs.

**Options comparison**

Here's a brief overview of each approach:

*   **Lodash `merge` method**: Pros:
    *   More flexible and powerful than Object.assign()
    *   Allows for more complex merge operations (e.g., merging arrays, objects with nested objects)
    *   Often used in production codebases
*   **Object.assign() method**: Cons:
    *   Less flexible than Lodash `merge`, as it only allows copying properties from source objects onto a target object.
    *   May not work well with complex data structures (e.g., arrays, nested objects).
*   **Spread operator (`...`)**: Pros:
    *   Simple and concise syntax
    *   Works well for simple merge operations
    *   Performance is often comparable to Object.assign()
*   Cons:
    *   Less flexible than Lodash `merge`, as it only allows copying properties from source objects onto a target object.

**Other considerations**

When choosing an approach, consider the specific requirements of your project:

*   If you need more complex merge operations or work with nested data structures, Lodash `merge` might be a better choice.
*   For simple, straightforward merges, Object.assign() or spread operator (`...`) could suffice.
*   If performance is critical, benchmarking these approaches on your specific use case will help determine the best approach.

**Library and syntax**

Lodash is a popular utility library for functional programming tasks. It provides an extensive set of functions for manipulating data, including `merge`, which is used in this benchmark.

The spread operator (`...`) is a shorthand syntax introduced in ECMAScript 2018 (ES8). It allows you to create new objects by copying properties from existing objects and adding new key-value pairs.

**Benchmark results**

Based on the latest benchmark result, it appears that:

*   The spread operator (`...`) outperforms Object.assign() but is slightly slower than Lodash `merge`.
*   The order of performance between these approaches may vary depending on the specific use case and data structures being merged.

Related benchmarks:

lodash merge vs object.assign vs spread v2 (version: 0)

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

Created: one year ago by: Guest

Jump to the latest result

lodash merge

object.assign

spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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