Benchmark: Slice vs spread array of objects

Tests:

Slice
const list = [{id: 'one'}, {id: 'two'}, {id: 'three'}] const listSlice = list.slice()
Spread
const list = [{id: 'one'}, {id: 'two'}, {id: 'three'}] const listSpread = [...list]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Slice
Spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is tested?**

The provided benchmark tests two approaches for creating an array slice from an existing array of objects:

1. **`list.slice()`**: This method creates a shallow copy of the original array by calling the `slice()` method, which returns a new array object referencing the same elements as the original array.
2. **`[...list]` (Spread syntax)**: This approach uses the spread operator (`...`) to create a new array containing all elements from the original array.

**Options compared**

The two approaches are compared in terms of their performance, with both browsers executing the test multiple times per second and providing raw UA strings, browser version, device platform, operating system, and execution count for each test case.

**Pros and Cons:**

1. **`list.slice()`**:
	* Pros:
		+ Lightweight and efficient, as it only creates a new reference to the original elements.
		+ Can be used with arrays of any type (not just objects).
	* Cons:
		+ May not work correctly when dealing with complex data structures or nested objects, as it only creates a shallow copy.
2. **`[...list]` (Spread syntax)**:
	* Pros:
		+ Creates a new array containing all elements from the original array, including nested objects and arrays.
		+ Can handle more complex data structures than `slice()`.
	* Cons:
		+ Can be slower due to the overhead of creating a new array.
		+ May not work correctly in older browsers or with specific edge cases.

**Library/ Framework Considerations**

There are no notable libraries or frameworks involved in this benchmark.

**Special JS Features/Syntax**

None mentioned in the provided code snippets, but it's worth noting that some modern JavaScript features like `const` declarations and arrow functions (`() => {}`) might affect performance depending on the specific use case. However, these aspects are not relevant to the specific benchmark being tested here.

**Alternatives**

Other alternatives for creating an array slice or spread of objects include:

* Using the `Array.prototype.slice.call()` method (not applicable in this scenario)
* Creating a new array using the `Array.from()` method (applicable, but not compared in this benchmark)

In summary, MeasureThat.net provides a simple yet informative way to compare the performance of two approaches for creating an array slice from an existing array of objects: `list.slice()` and `[...list]` (Spread syntax). By analyzing the pros and cons of each approach, developers can make informed decisions about which method is best suited for their specific use case.

Related benchmarks:

Slice vs spread array of objects (version: 0)

Comparing performance of: Slice vs Spread

Created: 4 years ago by: Guest

Jump to the latest result

Slice

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):