Benchmark: Object.assign vs spread operator new object

Tests:

Object.assign
var params = { b:"hello", c: true, d:7 }; var other = Object.assign({}, { a: 2 }, params);
spread operator
var params = { b:"hello", c: true, d:7 }; var other = { a: 2, ...params };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
spread operator

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.

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

**Benchmark Overview**

The benchmark is comparing two approaches for creating a new object: `Object.assign()` and the spread operator (`...`). The test case uses JavaScript, specifically in Firefox 79 on Windows Desktop.

**What is being tested?**

Two options are being compared:

1. **`Object.assign()`**: This method copies properties from an existing object to a new object. In this case, it's used to copy the `params` object to a new object (`other`). The pros of using `Object.assign()` include:
	* It's widely supported across browsers and Node.js versions.
	* It allows for flexible property merging.
However, its cons include:
	* Performance overhead due to function call and variable lookup.
	* Can be slower compared to other approaches like the spread operator.

2. **Spread Operator (`...`)**: This syntax creates a new object by copying properties from an existing object. In this case, it's used to create `other` by spreading the `params` object. The pros of using the spread operator include:
	* Faster performance compared to `Object.assign()`.
	* More readable and concise syntax.
However, its cons include:
	* Limited browser support (Firefox 79+).
	* May not work as expected in older browsers.

**Library**

The benchmark uses no external libraries besides JavaScript's built-in `Object` prototype. The spread operator is a part of the ECMAScript standard, which means it's supported across most modern browsers and Node.js versions.

**Special JS feature or syntax**

There are no special JavaScript features or syntax used in this benchmark beyond what's mentioned (spread operator). If you're familiar with JavaScript, you know that the spread operator was introduced in ECMAScript 2015 (ES6) as a way to create new objects by copying properties from an existing object.

**Alternative approaches**

Other alternatives for creating a new object include:

1. `Object.create()`: Creates a new object with a given prototype.
2. Object literal syntax: `{ a: 2, b: 'hello', c: true }`
3. `Array.prototype.slice()` or `Array.prototype.map()`: Can be used to create an array and then convert it to an object using the spread operator.

These alternatives might have different performance characteristics, syntax complexity, and browser support compared to `Object.assign()` and the spread operator.

Related benchmarks:

Object.assign vs spread operator new object (version: 0)

Comparing performance of: Object.assign vs spread operator

Created: 7 years ago by: Guest

Jump to the latest result

Object.assign

spread operator

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):