Benchmark: spread vs extends

HTML Preparation code:

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

Tests:

lodash
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = _.extend(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
spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the benchmark and explain what's being tested, compared, and considered.

**Benchmark Definition**

The benchmark is defined by two test cases: "spread" and "lodash". The goal of this benchmark is to compare the performance of two approaches:

1. **Lodash `_.extend()`**: This approach uses a library function to merge two objects.
2. **Spread syntax (`...`)**: This approach uses a new JavaScript feature to create a new object by spreading the properties of one or more source objects.

**Options Compared**

The benchmark compares the performance of these two approaches on two small sets of data (a and b, respectively). The test cases are identical except for how they define the `c` variable:

* In the "lodash" test case, `c` is created by calling the `_extend()` function from Lodash, which merges objects `a` and `b`.
* In the "spread" test case, `c` is created using the spread syntax (`...`) to create a new object that includes all properties from `a` and `b`.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Lodash `_extend()`**:
	+ Pros: Well-tested and efficient for merging objects.
	+ Cons: Requires including the Lodash library, which may impact performance due to additional overhead.
* **Spread syntax (`...`)**:
	+ Pros: Lightweight and easy to use. Does not require any external libraries.
	+ Cons: May be slower than `_extend()` for large datasets.

**Library Used**

In this benchmark, the `lodash.js` library is used by the "lodash" test case. Lodash is a popular JavaScript utility library that provides functions for tasks like merging objects (`_.extend()`). The spread syntax (`...`) is a built-in JavaScript feature introduced in ECMAScript 2015.

**Other Considerations**

* **Device and browser**: The benchmark results are reported for a specific Chrome browser version (79) on a Mac OS X 10.15.3 device.
* **Language support**: This benchmark only tests JavaScript, as it is designed to measure performance of these two approaches within the language.
* **Other alternatives**: Other methods for merging objects might be considered in alternative benchmarks, such as using `Object.assign()` or creating an object literal with multiple assignments.

Overall, this benchmark provides a simple and straightforward test of two common approaches to merging objects in JavaScript.

Related benchmarks:

spread vs extends (version: 0)

Comparing performance of: lodash vs spread

Created: 6 years ago by: Guest

Jump to the latest result

lodash

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):