Benchmark: Object.assing vs Object.entries

Script Preparation code:

var arr = [];
for(i=0; i<100; i++){
arr[i] = {id:i, value: i}
}

Tests:

Object.assing
const copy = [] arr.forEach((item,i)=> { copy[i] = Object.assign({}, item) }) console.log('copy-1',copy)
Object.entries
const copy = [] Object.entries(arr).forEach(([key, value]) => { copy[key] = value }) console.log('copy-2',copy)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assing
Object.entries

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.

I'll break down the provided JSON for MeasureThat.net and explain what's being tested.

**Benchmark Definition**

The benchmark is testing two approaches to create a copy of an array using objects:

1. `Object.assign()`
2. `Object.entries()` followed by a loop to create the copy object

**Options Compared**

Two options are compared:

* **Option 1: `Object.assign()`** - This method takes an existing object and creates a new object with copies of its enumerable properties.
* **Option 2: `Object.entries() + loop`** - This approach uses the `Object.entries()` method to get an array of key-value pairs from the original object, then loops through this array to create a new object with the same keys and values.

**Pros and Cons**

1. **`Object.assign()`**
	* Pros:
		+ Simple and concise.
		+ Fast, since it's just a simple property assignment.
	* Cons:
		+ Creates a shallow copy (i.e., only copies enumerable properties).
		+ Not suitable for large objects or complex data structures.
2. **`Object.entries() + loop`**
	* Pros:
		+ More flexible and powerful, as it allows for arbitrary key-value pairs.
	* Cons:
		+ Slower than `Object.assign()` due to the additional overhead of looping through the array.
		+ More verbose code.

**Other Considerations**

* **Array methods vs. object methods**: Both approaches use different methods to create a copy. While `Object.assign()` is optimized for copying objects, `Object.entries()` + loop can be more flexible but also slower.
* **Shallow vs. deep copies**: The current benchmark only tests shallow copies (i.e., only enumerable properties). If you need to test deep copies (i.e., all properties, including non-enumerable ones), additional modifications would be required.

**Library**

None of the provided code uses any external libraries that are not part of the standard JavaScript.

**Special JS Feature or Syntax**

The benchmark does not use any special JavaScript features or syntax beyond what's standard. However, it assumes that the `const` keyword is available (i.e., JavaScript 2015+).

Now, regarding alternative approaches:

* **Lodash**: A popular utility library for JavaScript that provides a deep copy method (`_.clone()`) which could be used to create a deep copy of an object.
* **JSON.parse()` + `JSON.stringify()`**: This approach can create a deep copy by serializing the original object as JSON and then deserializing it. However, this is slower than both `Object.assign()` and the `Object.entries() + loop` approach.

In conclusion, MeasureThat.net's benchmark provides valuable insight into the performance of different approaches to creating a copy of an array using objects in JavaScript.

Related benchmarks:

Object.assing vs Object.entries (version: 0)

test

Comparing performance of: Object.assing vs Object.entries

Created: 2 years ago by: Guest

Jump to the latest result

Object.assing

Object.entries

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):