Benchmark: lodash merge vs lodash 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);
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 };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge
lodash 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 break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing three ways to merge or assign objects in JavaScript:

1. **Lodash `merge`**: A utility function that recursively merges two objects into one, overwriting properties with conflicting keys.
2. **Lodash `assign`**: A utility function that assigns the values of one object to another, overwriting any existing keys.
3. **Spread operator (`...`)**: A syntax feature introduced in ECMAScript 2018, which creates a new object by copying all enumerable own properties from two or more source objects.

**Options Compared**

The benchmark is comparing these three options:

* `_.merge(a, b)`: Uses the Lodash `merge` function to combine `a` and `b`.
* `_.assign(a, b)`: Uses the Lodash `assign` function to merge `a` and `b`.
* `{ ...a, ...b }`: Uses the spread operator to create a new object by combining `a` and `b`.

**Pros and Cons**

Here's a brief summary of each approach:

* **Lodash `merge`**: Pros: Simple and easy to use. Cons: May be slower due to recursive merging.
* **Lodash `assign`**: Pros: Fast and efficient. Cons: May not work well with deeply nested objects or arrays.
* **Spread operator (`...`)**: Pros: Modern, fast, and concise. Cons: Requires ECMAScript 2018 support, may not work in older browsers.

**Library: Lodash**

Lodash is a popular JavaScript library that provides a collection of utility functions for tasks like merging objects, assigning values, and more. The `merge` and `assign` functions are part of the Lodash library.

**Special JS Feature/Syntax: Spread Operator**

The spread operator (`...`) is a new syntax feature introduced in ECMAScript 2018, which allows you to create a new object by copying all enumerable own properties from two or more source objects. This feature is supported in modern browsers like Chrome 71 and its derivatives.

**Other Alternatives**

If you're not using Lodash or the spread operator, you can also use other alternatives for merging and assigning objects:

* For `merge` functionality: You can create a custom function using `Object.assign()` and some helper logic to handle recursive merging.
* For `assign` functionality: You can use `Object.assign()` directly without Lodash.
* For spread operator (`...`): If you're targeting older browsers, you may need to use a polyfill or another library that supports this syntax.

Keep in mind that the benchmark is specifically comparing these three options, so it's likely that the authors are interested in measuring performance differences between them.

Related benchmarks:

lodash merge vs lodash assign vs spread (version: 0)

Comparing performance of: lodash merge vs lodash assign vs spread

Created: 7 years ago by: Guest

Jump to the latest result

lodash merge

lodash 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):