Benchmark: set.has vs. array.includes on big arrays sf

Script Preparation code:

var arr1 = Array.from({
    length: 1000
}, (_, i) => i + 1)

var arr2 = Array.from({
    length: 1000
}, (_, i) => i * 1000)

var set1 = new Set(arr1)
var set2 = new Set(arr2)

Tests:

includes
return arr2.filter(x => arr1.includes(x))
lookup
return [...set2].filter(x => set1.has(x))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
lookup

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark compares two approaches to check if an element exists in an array or set: `arr.includes()` (or its equivalent with spread syntax, `[...set].has(x)`) versus checking if an element is present in the underlying collection of the set (`set1.has(x)`).

**Options Compared**

There are three options being compared:

1. **`arr2.filter(x => arr1.includes(x))`**: This approach uses `includes()` on the original array `arr1` and filters out elements that aren't found.
2. **`[...set2].filter(x => set1.has(x))`**: This approach uses the spread syntax to convert the set to an array, then uses `has()` on the original underlying collection of the set (`set1`).
3. **A third option is implied but not explicitly defined in the provided benchmark**: We can assume it would be similar to options 1 and 2.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **`arr2.filter(x => arr1.includes(x))`**:
	* Pros: Simple, straightforward implementation.
	* Cons: May involve unnecessary iterations or lookups if `includes()` is slow.
2. **`[...set2].filter(x => set1.has(x))`**:
	* Pros: Uses the efficient underlying collection of the set for lookups, potentially faster than option 1.
	* Cons: Requires extra memory allocation and creation of an array using spread syntax.

**Library Usage**

The `Set` data structure is used in this benchmark. A `Set` is a collection of unique values that cannot be duplicated. Its main purpose is to provide fast lookup, insertion, and deletion operations.

**Special JavaScript Features or Syntax**

The benchmark uses the following special feature:

* **Spread syntax (`[...set2]`)**: This syntax allows converting a set (or an array) into an array using a concise syntax.

**Other Alternatives**

If we were to consider alternative approaches for this benchmark, we might explore:

* Using `map()` and checking if any elements match the target value.
* Using a custom implementation of `includes()` or `has()`.
* Comparing the performance with other languages or frameworks that have optimized set operations.

However, without more context, it's difficult to provide a comprehensive alternative set of benchmarks.

Related benchmarks:

set.has vs. array.includes on big arrays sf (version: 0)

Comparing performance of: includes vs lookup

Created: 4 years ago by: Guest

Jump to the latest result

includes

lookup

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):