Benchmark: JavaScript spread operator vs Object.assign performance22

Tests:

Using the spread operator
const firstObject = { "id": "GitHubJavaClient_BuildMaven", "internalId": "bt1161", "name": "Build (Maven)", "type": "regular", "paused": false, "projectId": "GitHubJavaClient" } const secondObject = { "id": "", "internalId": "", "name": ")", "type": "regular", "paused": true, "projectId": ""} const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { "id": "GitHubJavaClient_BuildMaven", "internalId": "bt1161", "name": "Build (Maven)", "type": "regular", "paused": false, "projectId": "GitHubJavaClient" } const secondObject = { "id": "", "internalId": "", "name": ")", "type": "regular", "paused": true, "projectId": ""} const finalObject = Object.assign(firstObject, secondObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign

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 provided benchmark definition and test cases.

**What is being tested?**

The benchmark compares two approaches to merge two objects in JavaScript:

1. Using the spread operator (`...`).
2. Using `Object.assign()`.

Both tests aim to create a new object by merging `firstObject` and `secondObject`. The resulting object will have all properties from both input objects.

**Options being compared**

In this case, we're comparing two methods for object merging:

1. **Spread operator (`...`)**: This syntax was introduced in ECMAScript 2018 (ES2018). It allows you to spread the properties of an object into another object using the `...` operator.
2. **`Object.assign()`**: This is a built-in JavaScript function that returns a new object with the properties copied from one or more source objects.

**Pros and cons**

**Spread Operator (`...`)**

Pros:

* Concise syntax
* Fast performance (since it only creates a shallow copy of the original object)
* Easy to read and understand

Cons:

* Limited support in older browsers (pre-ES2018)
* May not be suitable for large objects or complex merges due to its shallow copying nature

**`Object.assign()`**

Pros:

* Wide browser support (all versions since ES5)
* Can handle large objects and complex merges more efficiently
* More control over the merging process (e.g., using `mergeDeep()` in some libraries)

Cons:

* Less concise syntax compared to the spread operator
* May have performance overhead due to creating a new object

**Library usage**

Neither of the provided test cases uses any external library. However, if you were to add additional complexity or features, you might consider using a library like Lodash (`_.merge()`), which provides a more robust and flexible way to merge objects.

**Special JavaScript feature or syntax**

The spread operator is a relatively new feature introduced in ES2018 (ECMAScript 2018). If your target browser version is older than this, the spread operator might not be supported. In such cases, `Object.assign()` would be the default approach.

If you're targeting modern browsers with support for the spread operator, it's likely to provide better performance and readability compared to `Object.assign()`. However, if you need to support older browsers or have specific requirements, using `Object.assign()` might be a better option.

Related benchmarks:

JavaScript spread operator vs Object.assign performance22 (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign

Created: 3 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

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):