Benchmark: Array.prototype.slice(0) vs spread operator 99999

Script Preparation code:

var params = [];
for (let step = 0; step < 99999; step++) {
  params.push(step);
}

Tests:

Array.prototype.slice
var other = params.slice(0);
spread operator
var other = [ ...params ];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.slice
spread operator

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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I'll break down the provided benchmark definitions, explaining what's being tested and comparing different approaches.

**Benchmark Definition**
The first part of the json represents the overall benchmark definition:

```json
{
    "Name": "Array.prototype.slice(0) vs spread operator 99999",
    "Description": "Compare the new ES6 spread operator with the traditional slice(0) method",
    "Script Preparation Code": "var params = [];\r\nfor (let step = 0; step < 99999; step++) {\r\n  params.push(step);\r\n}",
    "Html Preparation Code": null
}
```

Here's what's being tested:

* The benchmark compares the performance of two methods for creating a shallow copy of an array:
	+ `Array.prototype.slice(0)`
	+ The ES6 spread operator `[ ...params ]`
* The test script creates an array `params` with 99,999 elements using a `for` loop.
* The `Html Preparation Code` is empty, indicating that no HTML-related code needs to be executed before the benchmark.

**Individual Test Cases**
The second part of the json represents individual test cases for each method:

```json
[
    {
        "Benchmark Definition": "var other = params.slice(0);",
        "Test Name": "Array.prototype.slice"
    },
    {
        "Benchmark Definition": "var other = [ ...params ];",
        "Test Name": "spread operator"
    }
]
```

Here's what's being tested for each method:

* `Array.prototype.slice(0)`: The benchmark measures the performance of calling `slice()` on the original array, effectively creating a shallow copy.
* `spread operator `[ ...params ]`: The benchmark measures the performance of using the spread operator to create a new array from the original elements.

**Pros and Cons**

### Array.prototype.slice(0)

Pros:

* Wide browser support: `slice()` is a built-in method in modern JavaScript engines, ensuring compatibility across various browsers.
* Easy to read and write: The code is straightforward, as it calls a built-in method.

Cons:

* Performance overhead: Creating a shallow copy using `slice()` might incur additional memory allocations and garbage collection.

### spread operator `[ ...params ]`

Pros:

* Efficient: Using the spread operator creates a new array without copying the original elements' references.
* Modern syntax: The spread operator is a newer feature, which might appeal to developers who prefer modern code.

Cons:

* Limited browser support: Although widely supported, some older browsers (e.g., Internet Explorer 11) may not support this syntax.
* Readability concerns: Some developers might find the spread operator syntax less readable than `slice()`.

**Library Usage**

None of the provided benchmark definitions explicitly use libraries. However, it's essential to note that in a real-world scenario, you might encounter libraries that provide alternative implementations for array manipulation methods like `slice()` or arrays' constructors.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax mentioned in this benchmark definition. The tests only involve built-in methods and basic array operations.

**Other Alternatives**

If you wanted to test different approaches, you could consider alternatives such as:

* Using `Array.from()` instead of the spread operator
* Implementing a custom array constructor or `slice()` method
* Using other shallow copy methods, like `concat()`
* Comparing performance with more modern JavaScript features, like `Array.prototype.reduce()`

Related benchmarks:

Array.prototype.slice(0) vs spread operator 99999 (version: 0)

Compare the new ES6 spread operator with the traditional slice(0) method

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

Created: 6 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):