Benchmark: Spread vs Obj Assign/Create v2

Tests:

Obj Assign/Create
const obj = {}; obj.parent = { sampleData: 'Hello world', foo(){ return 'bar'; } } obj.final = Object.assign(Object.create(obj.parent),{ moreData: 'foo bar' });
Obj Spread
const obj = {}; obj.parent = { sampleData: 'Hello world', foo(){ return 'bar'; } } obj.final = { ...obj.parent, moreData: 'foo bar' };

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Suite status: <idle, ready to run>

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Test case name	Result
Obj Assign/Create
Obj Spread

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in the provided benchmark.

The benchmark is comparing two approaches to create an object `obj` and assign properties to it: using `Object.assign()` with `Object.create()`, and using the spread operator (`...`). The objective of this benchmark is to measure the performance difference between these two approaches on JavaScript engines.

**Approach 1: Using Object.assign() with Object.create()**

This approach involves creating an object `obj` and then using `Object.create()` to create a new object that inherits from `obj`. Then, it uses `Object.assign()` to copy properties from the original `obj` into the new object. Finally, it adds more data to the new object.

**Pros:**

* This approach ensures that the new object has all the properties of the original `obj`, including inherited ones.
* It allows for better control over the creation process.

**Cons:**

* It can be slower due to the extra step of creating a new object using `Object.create()`.
* The resulting object may have more memory overhead due to the additional layer of inheritance.

**Approach 2: Using Spread Operator (`...`)**

This approach involves creating an object `obj` and then using the spread operator to create a new object that includes all properties from `obj`, plus any additional data provided directly in the new object.

**Pros:**

* This approach is generally faster since it eliminates the need for `Object.create()` and reduces memory overhead.
* It provides a more concise and expressive way of creating objects with shared properties.

**Cons:**

* The spread operator may not work correctly if the original object has inherited properties that are also present in the new object, leading to unexpected behavior or loss of data.
* This approach assumes that the additional data provided directly in the new object will overwrite any existing properties with the same name.

Now, let's take a look at the specific test cases:

1. `Obj Assign/Create`:
This test case uses the first approach mentioned above, where `Object.create()` is used to create a new object that inherits from the original `obj`. Then, it uses `Object.assign()` to copy properties from the original `obj` into this new object.
2. `Obj Spread`:
This test case uses the second approach mentioned above, where the spread operator (`...`) is used to create a new object that includes all properties from the original `obj`, plus any additional data provided directly in the new object.

In terms of special JavaScript features or syntax, there isn't anything specific that stands out here. However, it's worth noting that the use of `Object.create()` and the spread operator are both relatively modern features introduced in ECMAScript 2015 (ES6).

As for libraries, none are used in these test cases.

If you're interested in exploring alternative approaches or optimizations, some other alternatives could include:

* Using a library like Lodash's `cloneDeep` function to create deep copies of objects.
* Implementing a custom copying mechanism that avoids the use of `Object.assign()` and instead uses bitwise operations or other techniques to copy properties directly from one object to another.
* Optimizing the code to reduce memory allocations and garbage collection overhead, for example by reusing existing objects or using techniques like " proto-chaining" to minimize object creation.

Related benchmarks:

Spread vs Obj Assign/Create v2 (version: 1)

Comparing performance of: Obj Assign/Create vs Obj Spread

Created: 5 years ago by: Registered User

Jump to the latest result

Obj Assign/Create

Obj 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):