Benchmark: Small n set vs array

Script Preparation code:

var a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var b = new Set(a)

Tests:

array.includes
return a.includes(3)
set.has
return b.has(3)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.includes
set.has

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Linux

View result in a separate tab

Test name	Executions per second
array.includes	24932190.0 Ops/sec
set.has	24970362.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months 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 is designed to compare two approaches for checking if an element exists in a data structure:

1. Using an array (`includes` method)
2. Using a Set (`has` method)

**Script Preparation Code**

The script preparation code creates two data structures: `a` (an array) and `b` (a Set, initialized with the elements of `a`). This sets up the test environment for both scenarios.

```javascript
var a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var b = new Set(a);
```

**Options Compared**

The benchmark compares two options:

1. **Array `includes` method**: This checks if the specified element (`3`) exists in the array `a`.
2. **Set `has` method**: This checks if the specified element (`3`) exists in the Set `b`.

**Pros and Cons of Each Approach:**

**Array `includes` method:**

Pros:

* Wide support across browsers
* Easy to implement

Cons:

* May involve linear search, leading to O(n) time complexity
* Can be slower for large datasets

**Set `has` method:**

Pros:

* Fast lookups (O(1) average time complexity)
* Efficient for large datasets

Cons:

* Requires a Set data structure, which may not be supported in all browsers
* May require additional code to handle edge cases

**Library Used:**

The benchmark uses the built-in `Set` and array methods (`includes`, `has`) without any external libraries.

**Special JS Features or Syntax:**

None mentioned. Both scenarios use standard JavaScript features.

**Alternatives:**

Other alternatives for checking if an element exists in a data structure include:

* Using a Map (if you need to store additional metadata with each value)
* Implementing a custom lookup function using techniques like binary search
* Using libraries like Lodash or Ramda, which provide optimized implementations of these operations

For this specific benchmark, the Set `has` method is likely preferred due to its performance advantages. However, for more complex use cases or browsers that don't support Sets, the array `includes` method may still be a viable option.

Related benchmarks:

Small n set vs array (version: 0)

Comparing performance of: array.includes vs set.has

Created: one year ago by: Guest

Jump to the latest result

array.includes

set.has

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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