Benchmark: Spread vs slice test

Tests:

Spread
const foo = [1,2,3,4,5]; const spread = [...foo];
Slice
const foo = [1,2,3,4,5]; const slice = foo.slice();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Slice

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Linux; Android 8.0.0; LLD-AL10) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.101 Mobile Safari/537.36

Browser/OS: Chrome Mobile 75 on Android 8.0.0

View result in a separate tab

Test name	Executions per second
Spread	401362.3 Ops/sec
Slice	250784.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript benchmarks!

**What is being tested?**

The provided benchmark tests two approaches to create a new array from an existing one: using the spread operator (`...`) and the `slice()` method.

**Options compared:**

* Spread operator (`...`): creates a new array by copying elements from the original array.
* `slice()` method: returns a shallow copy of a portion of an array.

**Pros and Cons:**

* **Spread Operator (`...`)**:
	+ Pros:
		- Creates a new, independent array, which can be useful for immutable data structures or when working with functions that take arrays as arguments.
		- Can be more readable in some cases, especially when creating complex spreads.
	+ Cons:
		- Can create unnecessary memory allocations if not used carefully.
		- May be slower than `slice()` due to the overhead of creating a new array.
* `slice()` method:
	+ Pros:
		- Generally faster than the spread operator because it creates a shallow copy without allocating new memory.
		- Often preferred for performance-critical code or when working with large arrays.
	+ Cons:
		- Can return a reference to the original array if not used carefully (e.g., `slice(0)` returns an empty array).
		- May not be as readable in some cases, especially when creating complex slices.

**Library:**

None, just built-in JavaScript functionality.

**Special JS feature/syntax:**

The benchmark uses spread operator (`...`) and `slice()` method, both of which are standard JavaScript features. No special syntax or features are used here.

**Other alternatives:**

* `Array.prototype.concat()`: creates a new array by copying elements from the original array.
* `Array.prototype.map()`: creates a new array with transformed elements (not applicable in this case).
* Other libraries or frameworks may have optimized implementations of these operations, but the benchmark is designed to compare built-in JavaScript methods.

Keep in mind that these alternatives may offer different trade-offs in terms of performance, memory usage, and readability, depending on the specific use case.

Related benchmarks:

Spread vs slice test (version: 0)

Comparing performance of: Spread vs Slice

Created: 5 years ago by: Guest

Jump to the latest result

Spread

Slice

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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