Benchmark: Spread operator vs. slice

Tests:

Spread operator
var n = []; while(true) { n.push('asdf'); n = [...n]; if(n.length >= 100000) break; }
Slice()
var n = []; while(true) { n.push('asdf'); n.slice(); if(n.length >= 100000) break; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread operator
Slice()

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark definition and test cases to understand what is being tested.

**Benchmark Definition**

The benchmark definition describes two approaches to creating an array reference every time:

1. **Spread Operator**: This approach uses the spread operator (`...`) to create a new array reference from the existing array `n`. The syntax `n = [...n];` creates a shallow copy of the array, which is then assigned back to `n`.
2. **Slice()**: This approach uses the `slice()` method to create a new array reference from the existing array `n`.

**Options Compared**

The two approaches are compared in terms of performance.

**Pros and Cons**

* **Spread Operator**:
	+ Pros: Simple, concise syntax; works with arrays of any type.
	+ Cons: Can be slower due to the overhead of creating a new array reference.
* **Slice()**:
	+ Pros: Efficient use of `slice()` method, which is optimized by most browsers.
	+ Cons: Requires specific method call (`slice()`), which may not be as intuitive.

**Library**

In this benchmark, no external libraries are used. However, the `slice()` method is a built-in method in JavaScript.

**Special JS Feature or Syntax**

The spread operator (`...`) was introduced in ECMAScript 2015 (ES6) and has since become a standard feature in modern browsers. The use of `slice()` also relies on the fact that most browsers have optimized implementations of this method.

**Other Alternatives**

If you were to implement these approaches using a different language or framework, you might consider:

* Using an array constructor (`Array.from()`) instead of spread operator.
* Using a library like Lodash or Ramda for array manipulation.

In JavaScript, alternative approaches could include:

* Using `Object.assign()` or other methods to create a new array reference.
* Implementing custom logic to create a new array reference from scratch.

However, these alternatives are not relevant in this specific benchmark, which focuses on the performance comparison of spread operator and slice().

Overall, this benchmark provides a simple yet informative way to compare the performance of two common approaches to creating an array reference in JavaScript.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36

Browser/OS: Chrome 65 on Windows

View result in a separate tab

Test name	Executions per second
Spread operator	0.0 Ops/sec
Slice()	0.0 Ops/sec

Related benchmarks:

Spread operator vs. slice (version: 0)

Creating a "new" array reference every time

Comparing performance of: Spread operator vs Slice()

Created: 6 years ago by: Guest

Jump to the latest result

Spread operator

Slice()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):