Benchmark: Object creation 3

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/immutable/4.0.0-rc.12/immutable.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

var obj1 = {v1: 1, v2:2, v3:3, v4:4, v5:5, v6:5, v7:7, v8:8, v9:9, v10:10}

Tests:

Object spread
var obj2 = {...obj1}
Object.assign
var obj2 = Object.assign({}, obj1)
Babelified spread
var obj2 = _objectSpread({}, obj1);
nothing
obj1.v1; obj1.v2; obj1.v3; obj1.v4; obj1.v5; obj1.v6; obj1.v7; obj1.v8; obj1.v9; obj1.v10; obj1.v1; obj1.v2; obj1.v3; obj1.v4; obj1.v5; obj1.v6; obj1.v7; obj1.v8; obj1.v9; obj1.v10; obj1.v1; obj1.v2; obj1.v3; obj1.v4; obj1.v5; obj1.v6; obj1.v7; obj1.v8; obj1.v9; obj1.v10;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object spread
Object.assign
Babelified spread
nothing

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance can be a complex task, and this benchmark from MeasureThat.net provides a great example of how to compare different approaches.

**What is being tested?**

The benchmark tests the speed of three different methods for creating a shallow copy of an object:

1. **Object spread**: Using the syntax `{...obj1}` to create a new object with the same properties as `obj1`.
2. **`Object.assign()`**: Using the `Object.assign()` method to create a new object and then assigning the properties of `obj1` to it.
3. **Babelified spread**: Using the `_objectSpread()` function (which is a polyfill for the ES6 spread syntax) to create a new object with the same properties as `obj1`.

**Options compared**

The benchmark compares these three approaches:

* Object spread: `{...obj1}`
* `Object.assign()`: `var obj2 = Object.assign({}, obj1)`
* Babelified spread: `_objectSpread({}, obj1)` (note that this is a custom implementation, not the standard ES6 spread syntax)

**Pros and cons of each approach**

1. **Object spread**: This method is concise and easy to read, but it may not be supported in older browsers or environments.
2. **`Object.assign()`**: This method is widely supported, but it can lead to slower performance compared to other methods because it creates a new object and then assigns properties to it.
3. **Babelified spread**: This method is similar to the object spread syntax, but it uses a custom implementation instead of the standard ES6 syntax.

In general:

* Object spread is a good choice when you want a concise and easy-to-read solution, and you're sure your target environment supports it.
* `Object.assign()` is a safe choice when you need to support older browsers or environments.
* Babelified spread is a good alternative when you want a more efficient solution than object spread.

**Library: Immutable**

The benchmark includes the Immutable library (`https://cdnjs.cloudflare.com/ajax/libs/immutable/4.0.0-rc.12/immutable.min.js`), which provides a way to work with immutable data structures in JavaScript. In this case, it's used as a dependency for the object spread and Babelified spread tests.

**Special JS feature or syntax: ES6 spread syntax**

The benchmark uses the ES6 spread syntax (`{...obj1}`) to create an object copy. This syntax is widely supported in modern browsers and environments, but it may not be supported in older browsers or environments.

I hope this explanation helps!

Related benchmarks:

Object creation 3 (version: 0)

Comparing performance of: Object spread vs Object.assign vs Babelified spread vs nothing

Created: 4 years ago by: Registered User

Jump to the latest result

Object spread

Object.assign

Babelified spread

nothing

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):