Benchmark: Array.prototype.slice vs spread operator vs concat 2

Tests:

Array.prototype.slice
var params = [ "hello", true, 7 ]; var other = params.slice();
spread operator
var params = [ "hello", true, 7 ] var other = [ ...params ]
concat
var params = [ "hello", true, 7 ] var other = params.concat()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.slice
spread operator
concat

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its components.

**Benchmark Definition**

The provided JSON represents a benchmarking test for comparing three approaches to create a shallow copy of an array:

1. `Array.prototype.slice()`
2. The new ES6 spread operator (`[ ...params ]`)
3. The traditional `concat()` method (`params.concat()`)

These approaches are used to compare their performance, which is likely the primary purpose of this benchmark.

**Options Compared**

The three options being compared have different characteristics:

1. **`Array.prototype.slice()`**: This method creates a shallow copy of an array by returning a new array object with references to the original elements. It's a widely supported and well-established method.
2. **Spread Operator (`[ ...params ]`)**: Introduced in ES6, this operator allows for creating arrays from iterable objects (like arrays or strings). In this benchmark, it's used to create a shallow copy of an array by spreading its elements into a new array.
3. **`concat()` method**: This method creates a new array object and then copies the elements from the original array into the new one. It's also widely supported but can be slower than `slice()` due to its extra step.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **`Array.prototype.slice()`**
	* Pros: Fast, widely supported, and has been around for a long time.
	* Cons: Can be less intuitive for those new to JavaScript, as it returns a new array object with references to the original elements.
2. **Spread Operator (`[ ...params ]`)**
	* Pros: Concise and expressive, making it easier to read and write. Also creates an array with copies of the original elements.
	* Cons: May be slower than `slice()` due to its creation of a new array object. Introduced in ES6, so older browsers may not support it.
3. **`concat()` method**
	* Pros: Also creates an array with copies of the original elements.
	* Cons: Can be slower than `slice()`, and has an extra step of creating a new array object.

**Library Usage**

There is no library usage in this benchmark, as all three approaches are native JavaScript methods.

**Special JS Features or Syntax**

The spread operator (`[ ...params ]`) uses a feature introduced in ES6, which allows for creating arrays from iterable objects. This might be unfamiliar to some developers, but it's a common and useful syntax in modern JavaScript.

**Other Alternatives**

If you're looking for alternative approaches, consider:

1. **`Array.prototype.reduce()`**: Although not directly applicable here, `reduce()` can be used to create an array by accumulating elements from the original array.
2. **Custom implementation**: You could write your own custom function to create a shallow copy of an array, but this would likely be slower and less efficient than the native methods.

In summary, the benchmark compares three approaches to create a shallow copy of an array: `Array.prototype.slice()`, spread operator (`[ ...params ]`), and traditional `concat()` method. Each has its pros and cons, with `slice()` being fast and widely supported, while the spread operator is concise but may be slower.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36 OPR/80.0.4170.63

Browser/OS: Opera 80 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.prototype.slice	107526488.0 Ops/sec
spread operator	59105820.0 Ops/sec
concat	71339184.0 Ops/sec

Related benchmarks:

Array.prototype.slice vs spread operator vs concat 2 (version: 0)

Compare the new ES6 spread operator with the traditional slice() method

Comparing performance of: Array.prototype.slice vs spread operator vs concat

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.slice

spread operator

concat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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