Benchmark: JS object copy spread vs assign

Tests:

Assign
const object = {type: "gilada"}; const copy = Object.assign({}, object);
Spread
const object = {type: "gilada"}; const copy = {...object};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Assign
Spread

Fastest: N/A

Slowest: N/A

Latest run results:

No previous 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 world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The benchmark is testing two approaches to creating a copy of an object in JavaScript: using `Object.assign()` and using the spread operator (`...`). The benchmark is measuring which approach is faster, as well as the overhead of each method.

**Options compared:**

There are two options being compared:

1. **Assign**: Using `Object.assign()` to create a copy of an object.
2. **Spread**: Using the spread operator (`...`) to create a copy of an object.

**Pros and cons of each approach:**

* **Assign**:
	+ Pros:
		- Wide browser support
		- Easy to read and understand code
	+ Cons:
		- Can be slower than the spread operator, especially for large objects
		- May have performance implications due to the way it creates a new object in memory
* **Spread**:
	+ Pros:
		- Generally faster than `Object.assign()`
		- More concise and expressive code
	+ Cons:
		- May not be supported by older browsers or browsers with limited support for ES6 features

**Library usage:**

There is no explicit library mentioned in the benchmark definition or test cases. However, it's worth noting that both `Object.assign()` and the spread operator are built-in JavaScript methods.

**Special JS feature/syntax:**

The benchmark uses the spread operator (`...`), which is a relatively modern feature introduced in ES6 (ECMAScript 2015). This means that older browsers or environments may not support this syntax, although they may still execute it due to polyfills or other mechanisms. The benchmark assumes that the test environment supports ES6 features.

**Other considerations:**

* The benchmark only tests two approaches and does not consider other factors like object complexity, size, or nested structure.
* The results should be interpreted as a comparison of these two specific approaches rather than a comprehensive evaluation of all possible methods for creating object copies in JavaScript.
* MeasureThat.net provides additional information, such as browser versions and device platforms, which can help contextualize the benchmark results.

**Alternatives:**

If you're interested in exploring other ways to create object copies in JavaScript, consider the following alternatives:

1. **Array.prototype.slice()**: Creating a shallow copy of an array using `slice()` is another common approach.
2. **JSON.parse(JSON.stringify(object))**: Using `JSON.parse` and `JSON.stringify` can create a deep copy of an object.
3. **Object.assign()` with Object.create()**: This method creates a new object by copying existing properties from the original object.

Keep in mind that each of these alternatives has its own trade-offs, pros, and cons, which may not be immediately apparent without testing them thoroughly.

Related benchmarks:

JS object copy spread vs assign (version: 0)

Comparing performance of: Assign vs Spread

Created: 7 years ago by: Guest

Jump to the latest result

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):