Benchmark: JavaScript spread operator vs Object.assign performance 5

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } 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

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**Benchmark Overview**

The measure that net benchmark is comparing two approaches for merging two objects in JavaScript: using the spread operator (`...`) and `Object.assign()`.

**Options Compared**

* **Spread Operator (`...`)**: This approach uses the spread operator to merge two objects. The syntax `{ ...firstObject, ...secondObject }` creates a new object with all properties from both `firstObject` and `secondObject`.
* **`Object.assign()`**: This approach uses the `Object.assign()` method to merge two objects. The syntax `Object.assign({}, firstObject, secondObject)` creates a new object with all properties from both `firstObject` and `secondObject`.

**Pros and Cons**

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

Pros:

* More concise and expressive
* Easier to read and understand
* Can be used with arrays as well (e.g., ` [...arr, ...newArr]`)

Cons:

* Not supported in older browsers
* May have performance implications due to the creation of a new object

**`Object.assign()`**

Pros:

* Wide browser support
* Allows for merging multiple objects at once

Cons:

* Less concise and less expressive than the spread operator
* Requires a function call, which can be slower

**Other Considerations**

Both approaches create a new object with merged properties. However, the spread operator creates an object literal directly, while `Object.assign()` uses a function to merge objects.

In terms of performance, both approaches have their trade-offs:

* The spread operator is generally faster because it avoids the overhead of creating a function call.
* However, modern browsers have optimized `Object.assign()` for performance, making it competitive with the spread operator in many cases.

**Library and Special Features**

Neither test case uses any libraries or special JavaScript features other than the standard `Object` class and its methods (`assign()`, `...`). The use of spreads is a built-in feature introduced in ECMAScript 2018 (ES2018).

**Alternatives**

Other alternatives for merging objects include:

* **Lodash's `_.merge()`**: A popular utility library that provides an efficient way to merge objects.
* **Object.values()`, `Object.entries()`, and `reduce()`**: These methods can be used to create a new object by iterating over the values or entries of two objects.

In conclusion, the measure that net benchmark is primarily concerned with comparing the performance of two approaches for merging objects: using the spread operator (`...`) and `Object.assign()`. While both approaches have their pros and cons, the choice between them ultimately depends on personal preference, code readability, and the specific use case.

Related benchmarks:

JavaScript spread operator vs Object.assign performance 5 (version: 0)

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

Created: 5 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):