Benchmark: Slice vs Spread 260422

Tests:

slice
const list = [1, 2, 3] const copy = list.slice();
spread
const list = [1, 2, 3] const copy = [...list];

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Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
spread

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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Let's break down the provided benchmark and explain what's being tested.

**What is being tested?**

The benchmark compares two approaches to create a copy of an array in JavaScript: using the `slice()` method versus using the spread operator (`...`).

**Options compared:**

1. **Slice() method**: This method returns a shallow copy of a portion of an array.
2. **Spread operator (`...`)**: This operator creates a new array by spreading elements from an existing array.

**Pros and cons of each approach:**

1. **Slice() method**:
	* Pros:
		+ Efficient for large arrays, as it only creates a new reference to the original data.
		+ Fast execution time.
	* Cons:
		+ Only creates a shallow copy, which means that any nested objects or arrays within the original array will be copied by reference.
2. **Spread operator (`...`)**:
	* Pros:
		+ Creates a deep copy of the array, ensuring that all nested objects and arrays are fully cloned.
		+ Can be more intuitive for simple cases, as it's easier to read than `slice()`.
	* Cons:
		+ Generally slower execution time compared to `slice()` for large arrays.
		+ May have performance implications if used with very large arrays.

**Library usage:**

Neither of the approaches in this benchmark uses any external libraries. The `slice()` method is a built-in JavaScript function, while the spread operator (`...`) was introduced in ECMAScript 2015 (ES6).

**Special JS feature or syntax:**

The use of the spread operator (`...`) in the benchmark is an example of a newer JavaScript feature that has been adopted by modern browsers. While it's not strictly necessary to understand this syntax to grasp the concept, being aware of its existence can help developers make more informed decisions about array manipulation in their code.

**Other alternatives:**

For creating copies of arrays in JavaScript, other approaches include:

1. `Array.prototype.slice.call()`: This method creates a new array by calling the `slice()` function on an existing array.
2. `Object.assign()`: While not specifically designed for copying arrays, this method can be used to create a shallow copy of an object (including arrays).
3. `Array.from()`: While primarily used for creating new arrays from iterables, it can also be used with the spread operator (`...`) to create a copy of an array.

These alternatives may have slightly different performance characteristics or implications, depending on the specific use case and requirements.

In summary, the benchmark compares two approaches to create a copy of an array in JavaScript: using the `slice()` method versus using the spread operator (`...`). The choice between these methods depends on factors such as performance requirements, code readability, and the need for deep copying.

Related benchmarks:

Slice vs Spread 260422 (version: 0)

Comparing performance of: slice vs spread

Created: 4 years ago by: Guest

Jump to the latest result

slice

spread

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):