Benchmark: Array.prototype.slice vs spread operator fork

Tests:

Array.prototype.slice
var params = [ "hello", true, 7, 555.55 ]; var other = params.slice();
spread operator
var params = [ "hello", true, 7, 555.55 ] var other = [ ...params ]

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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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Measuring the performance of different approaches to create a copy of an array in JavaScript can be crucial for optimizing code and improving performance.

**Benchmark Overview**

The provided benchmark compares two ways to create a copy of an array: using the `Array.prototype.slice()` method and the new ES6 spread operator (`[...params]`). The test cases are designed to measure the performance difference between these two approaches.

**Options Compared**

There are two options compared:

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.
2. **New ES6 spread operator (`[...params]`)**: This operator creates a new array by iterating over the elements of the original array and creating a new element for each one.

**Pros and Cons**

### `Array.prototype.slice()`

Pros:

* Widely supported across different browsers and versions
* Easy to understand and implement
* Can be used in combination with other methods to create more complex copies

Cons:

* Creates a shallow copy, which means that if the original array contains objects or arrays as elements, only the references to these elements are copied, not the actual objects/arrays themselves.
* Can be slower than the spread operator for large arrays.

### New ES6 Spread Operator (`[...params]`)

Pros:

* Creates a deep copy of an array by creating new objects for each element
* Often faster than `slice()` for large arrays
* Is part of the modern JavaScript standard library, making it widely supported

Cons:

* May not be supported in older browsers or versions
* Can be less intuitive to use than `slice()`

**Library/Functionality**

There is no specific library used in this benchmark. The spread operator is a built-in feature of modern JavaScript.

**Special JS Feature/Syntax**

The benchmark uses the new ES6 spread operator, which was introduced in ECMAScript 2015 (ES6). This feature allows for concise and expressive array creation.

**Other Alternatives**

In addition to `Array.prototype.slice()` and the spread operator, there are other ways to create a copy of an array in JavaScript:

* Using `Array.from()`: This method creates a new array from an iterable or an array-like object. It can be used to create a deep copy of an array.
* Using `JSON.parse(JSON.stringify())`: This method can be used to create a deep copy of an array, but it's not as efficient as the spread operator.

Overall, the choice between using `Array.prototype.slice()` and the new ES6 spread operator depends on the specific use case and performance requirements. If you need a shallow copy of an array and don't care about the details, `slice()` might be sufficient. However, if you need a deep copy or are working with large arrays, the spread operator is likely to be faster and more efficient.

Related benchmarks:

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

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

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

Created: 7 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):