Benchmark: Big spread vs assign asdf

Tests:

Object.assign
const firstObject = { sampleData: 'Hello world' } for (let i = 0; i < 10000; i++) { firstObject[i] = { 'a': 'asdvasdv', 'b': 'bsdbsdfgsdfg', 'c': 'advadsfbasdg', 'd': 'vbsdfgadfgdfg' } } const secondObject = { 1: 'foo bar' } const finalObject = Object.assign(firstObject, secondObject);
Spread
const firstObject = { sampleData: 'Hello world' } for (let i = 0; i < 10000; i++) { firstObject[i] = { 'a': 'asdvasdv', 'b': 'bsdbsdfgsdfg', 'c': 'advadsfbasdg', 'd': 'vbsdfgadfgdfg' } } const secondObject = { 1: 'foo bar' } const finalObject = {...firstObject, secondObject}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
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):

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark compares two approaches to merge objects in JavaScript: `Object.assign()` and using the spread operator (`{...firstObject, secondObject}`). The benchmark is designed to test which approach performs better on a large dataset.

**Options Compared**

Two options are being compared:

1. **`Object.assign()`**: This method takes an existing object as a target and merges it with one or more source objects.
2. **Spread Operator (`{...firstObject, secondObject}`)**: This syntax is used to create a new object by copying all own enumerable properties from the first object (`firstObject`) and adding new ones from the second object (`secondObject`).

**Pros and Cons**

* **`Object.assign()`**:
	+ Pros:
		- Well-documented and widely supported.
		- Can handle objects with nested structures.
	+ Cons:
		- Can be slower than the spread operator due to the overhead of creating an intermediate array.
		- Does not support all object properties (e.g., getters, setters).
* **Spread Operator (`{...firstObject, secondObject}`)**:
	+ Pros:
		- Faster than `Object.assign()` because it avoids the overhead of creating an intermediate array.
		- Supports all object properties (getters, setters).
	+ Cons:
		- May not be as well-known or widely supported as `Object.assign()`.
		- Can lead to unexpected behavior if used incorrectly.

**Library and Special JS Features**

In this benchmark, no external libraries are used. However, the spread operator syntax relies on a feature introduced in ECMAScript 2018 (ES2018), which is widely supported by modern browsers and JavaScript engines.

**Test Case Explanation**

The test case creates an object `firstObject` with 10,000 properties and assigns a nested structure to each property. It then creates a second object `secondObject` with one property and merges it with `firstObject` using both `Object.assign()` and the spread operator syntax.

**Alternatives**

Other alternatives for merging objects in JavaScript include:

1. **Lodash's `merge()` function**: A popular utility library that provides a flexible way to merge objects.
2. **JavaScript's built-in `Array.prototype.reduce()` method**: Can be used to merge objects, but is less efficient than the spread operator or `Object.assign()`.
3. **Using a custom function to iterate over the object properties and assign values**: A more low-level approach that requires manual handling of property names and values.

In summary, this benchmark compares two common approaches for merging objects in JavaScript: `Object.assign()` and the spread operator syntax. While `Object.assign()` is widely supported and well-documented, the spread operator syntax offers a faster alternative while maintaining compatibility with modern browsers and JavaScript engines.

Related benchmarks:

Big spread vs assign asdf (version: 0)

Comparing performance of: Object.assign vs Spread

Created: 2 years ago by: Guest

Jump to the latest result

Object.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):