Benchmark: Array.prototype.slice vs spread operator (v2)

Tests:

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

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Suite status: <idle, ready to run>

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Test case name	Result
Array.prototype.slice
spread operator

Fastest: N/A

Slowest: N/A

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

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I'd be happy to explain what's being tested in the provided JSON benchmark.

The benchmark is comparing two approaches to create a copy of an array:

1. **`Array.prototype.slice()`**: This method returns a shallow copy of a portion of an array, starting from the specified index (0) and ending at the specified end index.
2. **Spread operator (`[...params]`)**: The spread operator is a new syntax in JavaScript that allows you to create a new array by spreading out elements from an existing array.

**Options being compared:**

* `Array.prototype.slice()` vs spread operator

**Pros and Cons of each approach:**

1. **`Array.prototype.slice()`**:
	* Pros:
		+ Widely supported and well-established method.
		+ Generally faster, since it only creates a reference to the original array.
	* Cons:
		+ Only returns a shallow copy (i.e., all nested arrays are preserved).
		+ Can be less intuitive for developers who are not familiar with the method.
2. **Spread operator (`[...params]`)**:
	* Pros:
		+ More concise and expressive syntax.
		+ Creates a deep copy of the array, preserving all nested arrays.
	* Cons:
		+ Not as widely supported as `Array.prototype.slice()`, although it has been in the language since ES6 (2015).
		+ Generally slower, since it creates a new array with multiple assignments.

**Other considerations:**

When deciding between these two approaches, consider the following factors:

* **Performance**: If you're dealing with very large arrays or performance-critical code, `Array.prototype.slice()` might be a better choice due to its potential speed advantage.
* **Code readability**: If you want to write more concise and expressive code, the spread operator might be a better fit. However, if you need to explain your code to others or are working with legacy JavaScript environments, `Array.prototype.slice()` might be a better option.
* **Nesting**: If your arrays contain nested arrays, the spread operator will create a deep copy, while `Array.prototype.slice()` only creates a shallow copy.

**Library usage:**

There is no external library used in this benchmark. Both approaches rely on built-in JavaScript functionality.

**Special JS features or syntax:**

The spread operator is a new feature introduced in ECMAScript 2015 (ES6). It's called the "spread syntax" and allows you to expand an array into separate arguments for a function.

**Alternatives:**

If you don't want to use either `Array.prototype.slice()` or the spread operator, you could consider other methods to create an array copy:

* **`Array.prototype.concat()`**: This method creates a new array by concatenating multiple arrays. However, it can be slower and more verbose than using `Array.prototype.slice()` or the spread operator.
* **Manual array creation**: You can manually create a new array by assigning each element of the original array to a new variable in an array.

Keep in mind that these alternatives may have different performance characteristics and code readability implications compared to the methods being tested.

Related benchmarks:

Array.prototype.slice vs spread operator (v2) (version: 0)

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

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

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.slice

spread operator

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):