Benchmark: Object.assign vs batch Object.assign

HTML Preparation code:

<script>
    const a = {
        foo: 'foo',
        bar: 'bar',
        baz: 'baz',
        qux: 'qux'
    }
    const b = {
        a: 'a',
        b: 'b',
        c: 'c',
        d: 'd',
        e: 'e',
        f: 'f'
    }
    const batch = [a, b, a, b, a, b, a, b, a, b]
</script>

Tests:

Object.assign
Object.assign({}, a, b) Object.assign({}, a, b) Object.assign({}, a, b) Object.assign({}, a, b) Object.assign({}, a, b)
Batch Object.assign
Object.assign({}, ...batch)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
Batch Object.assign

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 9 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark test.

**What is being tested?**

The benchmark tests the performance of two different approaches for using `Object.assign()` in JavaScript:

1. **Sequential Object Assign**: This approach uses `Object.assign()` multiple times with the same source objects (`a` and `b`) in a sequence. For example: `Object.assign({}, a, b)`, `Object.assign({}, a, b)`, etc.
2. **Batched Object Assign**: This approach uses `Object.assign()` once with an array of source objects (`batch`) passed as the second argument. For example: `Object.assign({}, ...batch)`.

**Options compared**

The two options being compared are:

* Sequential execution of `Object.assign()`
* Batching of `Object.assign()` with an array of source objects

**Pros and Cons of each approach**

* **Sequential Object Assign**: This approach is simple and easy to understand, but it may be slower due to the repeated function calls. Each call to `Object.assign()` creates a new object and copies the properties from the original object to the new one, which can lead to unnecessary memory allocations.
* **Batched Object Assign**: This approach can be faster because it reduces the number of function calls and creates only one new object with all the properties from the batch. However, it may require more memory to store the array of source objects.

**Library used**

In this benchmark, `Object.assign()` is a built-in JavaScript method that is part of the ECMAScript Standard Library. It's a simple way to copy the properties from one or more source objects to a target object.

**Special JS feature/syntax**

There are no special JavaScript features or syntax being tested in this benchmark. The code uses only standard JavaScript syntax and built-in methods.

**Other alternatives**

If you're looking for alternative ways to achieve similar results, here are a few options:

* Using `for...in` loop: You can use a `for...in` loop to iterate over the properties of an object and assign them to another object.
* Using `Object.create()`: You can use `Object.create()` to create a new object that inherits properties from an existing object.
* Using a library like Lodash or Immutable.js: These libraries provide alternative ways to perform object assignments, such as using `_.merge()` or `Immutable.Map().merge()`, which may offer better performance and flexibility.

However, for this specific benchmark, the results are already optimized for JavaScript's built-in `Object.assign()` method.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.96 Safari/537.36 Edg/88.0.705.56

Browser/OS: Chrome 88 on Windows

View result in a separate tab

Test name	Executions per second
Object.assign	365880.8 Ops/sec
Batch Object.assign	1057972.0 Ops/sec

Related benchmarks:

Object.assign vs batch Object.assign (version: 0)

Comparing performance of: Object.assign vs Batch Object.assign

Created: 3 years ago by: Guest

Jump to the latest result

Object.assign

Batch Object.assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 9 days ago):