Benchmark: lodash merge vs object.assign vs spread new obj

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var a = { a: 'oh', b: 'my' };
var b = { c: 'goddess', d: 'a', e: 'b', j: { asd: 'test' } };

Tests:

lodash merge
var c = _.merge({}, a, b);
object.assign
var c = Object.assign({}, a, b);
spread
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: 6 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser/OS: Chrome 141 on Windows

View result in a separate tab

Test name	Executions per second
lodash merge	1621368.4 Ops/sec
object.assign	13696075.0 Ops/sec
spread	13889735.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a benchmarking test created on MeasureThat.net, which compares the performance of three approaches for merging two objects: Lodash's `merge` function, `Object.assign`, and spread operator (`...`). The goal is to determine which method is the most efficient.

**Options Compared**

1. **Lodash's `merge` function**: This approach uses a library (Lodash) to merge the two objects.
2. **`Object.assign`**: This approach uses a built-in JavaScript method to merge the two objects.
3. **Spread operator (`...`)**: This approach uses a new feature in modern JavaScript to create a new object by spreading the properties of two existing objects.

**Pros and Cons**

1. **Lodash's `merge` function**:
	* Pros: Well-tested, widely used library; provides a flexible way to merge objects with custom logic.
	* Cons: Requires including an additional library, which may increase load times.
2. **`Object.assign`**:
	* Pros: Built-in method; fast and lightweight.
	* Cons: Only available in modern browsers (ECMAScript 2015+); may not work in older browsers.
3. **Spread operator (`...`)**:
	* Pros: Modern JavaScript feature; concise syntax; no additional libraries required.
	* Cons: May not be supported in older browsers or environments; requires ES6+ support.

**Library and Syntax**

The benchmark uses Lodash's `merge` function, which is a utility library for functional programming. The spread operator (`...`) is a new feature introduced in ECMAScript 2015 (ES6).

**Benchmark Preparation Code**

The provided script preparation code sets up two objects, `a` and `b`, to be merged:
```javascript
var a = { a: 'oh', b: 'my' };
var b = { c: 'goddess', d: 'a', e: 'b', j: { asd: 'test' } };
```
**Other Alternatives**

If you're interested in exploring alternative approaches, here are some options:

1. **JSON merge libraries**: Other libraries like `jsonmerge` or `deepmerge` can be used instead of Lodash's `merge`.
2. **Other built-in methods**: The `reduce()` method or a custom loop could be used to merge objects.
3. **Template literals**: A newer feature, template literals (``${...}``) could be used to concatenate object properties.

Keep in mind that the performance differences between these approaches may vary depending on your specific use case and environment.

Related benchmarks:

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

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

Created: 7 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

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