Benchmark: Objects spread vs object assign with large object

Tests:

Object.assign
// Object.assign function createObject(fillValue) { return Object.fromEntries(new Array(1024*12).fill(fillValue).map((value, index) => { return [fillValue + index, fillValue + index]; })); } const params = createObject('params'); const other = Object.assign(createObject('assign'), params);
spread operator
// spread operator function createObject(fillValue) { return Object.fromEntries(new Array(1024*12).fill(fillValue).map((value, index) => { return [fillValue + index, fillValue + index]; })); } const params = createObject('params'); const other = {...createObject('spread'), ...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

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

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Let's break down the benchmark and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Overview**

The benchmark compares two ways to create large objects in JavaScript: using the traditional `Object.assign()` method and the new ES6 spread operator (`...`).

**Script Preparation Code**

The script preparation code is not provided, but it's assumed that both test cases use the same underlying logic to generate a large object with 1024*12 properties.

For the "spread operator" test case, the code uses `Object.fromEntries()` method, which is a part of the JavaScript standard library. This method creates an object from an array of key-value pairs.

**Library Used:**

In this case, the `Object.fromEntries()` method is used as a helper function to generate the large object.

**Test Cases**

There are two test cases:

1. **"Object.assign"**: This test case uses the traditional `Object.assign()` method to create the large object.
2. **"spread operator"**: This test case uses the new ES6 spread operator (`...`) to create the large object.

**Pros and Cons of Each Approach**

* **`Object.assign()`**:
	+ Pros: widely supported, efficient in older browsers (before Chrome 100).
	+ Cons: can be slower due to the method call overhead.
* **Spread Operator (`...`)**:
	+ Pros: concise, faster, and more modern syntax.
	+ Cons: not supported in older browsers (before Chrome 100).

**Other Considerations**

* **Performance**: The spread operator is generally faster than `Object.assign()` due to its simpler syntax and lack of method call overhead.
* **Readability**: Both approaches are relatively readable, but the spread operator provides a more concise way to create large objects.

**Alternatives**

If you need to support older browsers (before Chrome 100), you may consider using other libraries or polyfills to implement the spread operator. Some alternatives include:

* Lodash's `_.assign()` method
* A library like `object-assign` for compatibility with older browsers

Keep in mind that if you're targeting modern browsers and want to take advantage of the spread operator, it's likely a better choice.

For those interested in learning more about JavaScript features or syntax, some notable mentions include:

* `Object.fromEntries()`: introduced in ECMAScript 2017.
* `...` spread operator: introduced in ECMAScript 2015 (ES6).

These features have improved performance and readability in modern JavaScript development.

Related benchmarks:

Objects spread vs object assign with large object (version: 1)

Compare the new ES6 spread operator with the traditional Object.assign() method large object

Comparing performance of: Object.assign vs spread operator

Created: 4 years ago by: Registered User

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):