Benchmark: lodash assign again 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 = _.assign(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

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The MeasureThat.net benchmark compares the performance of three approaches for merging two objects: `_.assign` from the Lodash library, `Object.assign`, and the spread operator (`{ ...a, ...b }`).

**Options Compared**

1. **Lodash _.assign**: This method merges two or more objects into a new object, allowing you to specify an optional options object.
2. **Object.assign**: This method copies all enumerable own properties from one or more source objects to a destination object.
3. **Spread Operator (`{ ...a, ...b }`)**: This syntax creates a new object by copying all enumerable properties from two or more sources (in this case, `a` and `b`).

**Pros and Cons of Each Approach**

1. **Lodash _.assign**:
	* Pros: Provides a flexible way to merge objects, allowing you to specify options for handling certain properties.
	* Cons: Requires the Lodash library, which may introduce additional overhead.
2. **Object.assign**:
	* Pros: Simple and straightforward, with no additional libraries required.
	* Cons: Does not provide as much control over the merging process as _.assign does.
3. **Spread Operator (`{ ...a, ...b }`)**:
	* Pros: Concise and easy to read, with no additional libraries required.
	* Cons: Only works in modern browsers that support the spread operator.

**Library Descriptions**

1. **Lodash**: A popular JavaScript utility library that provides a wide range of functions for tasks such as array manipulation, object merging, and more.

**JavaScript Feature/ Syntax Explanation**

The benchmark uses the spread operator (`{ ...a, ...b }`) in the third test case. This syntax was introduced in ECMAScript 2018 (ES8) and allows you to create a new object by copying all enumerable properties from two or more sources.

**Other Alternatives**

1. **Object.merge()**: Some older versions of Node.js provided an `Object.merge()` method, which is similar to `_.assign` but with some differences in syntax and behavior.
2. **Merge functions from other libraries**: Other JavaScript libraries, such as Underscore.js or Ramda, may provide their own merge functions that can be used instead of _.assign.

In summary, the MeasureThat.net benchmark provides a useful comparison of three approaches for merging objects: Lodash _.assign, Object.assign, and the spread operator. Understanding the pros and cons of each approach can help developers choose the best method for their specific use case.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36

Browser/OS: Chrome 70 on Mac OS X 10.13.6

View result in a separate tab

Test name	Executions per second
lodash merge	2278860.2 Ops/sec
object.assign	3853782.5 Ops/sec
spread	3787295.8 Ops/sec

Related benchmarks:

lodash assign again 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>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):