Benchmark: Filter array based on another array

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/uuid/8.3.2/uuid.min.js'></script>

Script Preparation code:

var assignments = []

for (i = 0; i < 50; i++) {
  assignments.push({ externalId: uuid.v4() })
}

function testIncludes() {
  var externalIdsArray = []
  
  for (i = 0; i < 50; i++) {
    externalIdsArray.push(uuid.v4())
  }
  
  assignments.filter(a => externalIdsArray.includes(a.externalId))
}

function testSet() {
  var externalIdsSet = new Set()
  
  for (i = 0; i < 50; i++) {
    externalIdsSet.add(uuid.v4())
  }
  
  assignments.filter(a => externalIdsSet.has(a.externalId))
}

function testMap() {
  var externalIdsMap = new Map()
  
  for (i = 0; i < 50; i++) {
    externalIdsMap.set(uuid.v4(), 1)
  }
  
  assignments.filter(a => externalIdsMap.has(a.externalId))
}

Tests:

Test includes
testIncludes()
Test set
testSet()
Test map
testMap()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Test includes
Test set
Test map

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and explain what's being tested, the options compared, pros and cons of each approach, and other considerations.

**Benchmark Definition:**

The benchmark defines three test cases:

1. `testIncludes()`: Tests if an array contains a specific element using the `includes()` method.
2. `testSet()`: Tests if an array contains a specific element using a `Set` data structure.
3. `testMap()`: Tests if an array contains a specific key-value pair using a `Map` data structure.

**Options Compared:**

The benchmark compares three different approaches to filter an array based on another array:

* `includes()` method
* Using a `Set`
* Using a `Map`

Each approach has its pros and cons:

* `includes()` method:
	+ Pros: Simple, widely supported, and efficient for small arrays.
	+ Cons: Can be slow for large arrays due to the need to iterate over the entire array. May not work efficiently if the array is very large or has a lot of duplicate elements.
* Using a `Set`:
	+ Pros: Fast lookup times, can handle large arrays without performance issues, and is suitable for scenarios where uniqueness is key.
	+ Cons: Requires extra memory to store the set, may not be as intuitive for developers who are not familiar with sets.
* Using a `Map`:
	+ Pros: Similar to using a `Set`, but provides additional functionality like key-value pairs. Can be useful if the array contains additional data that needs to be associated with each element.
	+ Cons: Requires extra memory to store the map, and may not be as efficient as using a `Set` for simple lookup scenarios.

**Library and its Purpose:**

The benchmark uses the `uuid` library, which generates unique identifiers (UUIDs) for elements in the array. The UUID is used to simulate an external ID that needs to be matched against an array of IDs. The purpose of the `uuid` library is to generate a unique identifier that can be used to identify each element in the array.

**Special JS Feature/Syntax:**

The benchmark uses the `includes()` method, which was introduced in ECMAScript 2015 (ES6). This method provides a simple and efficient way to check if an array contains a specific element. The `Set` and `Map` approaches also rely on modern JavaScript features.

**Other Considerations:**

* The benchmark measures the execution time of each test case, which is useful for identifying performance bottlenecks.
* The benchmark uses a fixed input size (50 elements) for simplicity, but in a real-world scenario, the input size may vary.
* The benchmark does not consider other factors that might affect performance, such as the specific browser or device being used.

**Alternatives:**

Other approaches to filter an array based on another array include:

* Using `forEach()` and a flag variable to track whether an element is found
* Using `findIndex()` to find the index of the first matching element
* Using `every()` to check if all elements in one array match the condition in another array

These alternatives may have different performance characteristics or use cases, depending on the specific requirements of the application.

Related benchmarks:

Filter array based on another array (version: 4)

Comparing performance of: Test includes vs Test set vs Test map

Created: 5 years ago by: Registered User

Jump to the latest result

Test includes

Test set

Test map

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):