Benchmark: filter ids with findIndex vs Map access12314

Tests:

findIndex
const questionIds = Array.from({length: 100}, () => { const index = Math.floor(Math.random() * 100); return {name: `test${index}`, id: index}; }); const allQuestions = Array.from({length: 100}, (_, i) => { const index = i + 1; return {name: `test${index}`, id: index}; }); const selectedQuestions = []; for (const questionId of questionIds) { const questionIdIndex = allQuestions.findIndex(question => question.id === questionId); if (questionIdIndex !== -1) { selectedQuestions.push(allQuestions[questionIdIndex]); } }
Map
const questionIds = Array.from({length: 100}, () => { const index = Math.floor(Math.random() * 100); return {name: `test${index}`, id: index}; }); const allQuestions = Array.from({length: 100}, (_, i) => { const index = i + 1; return {name: `test${index}`, id: index}; }); const questionMap = new Map(); allQuestions.forEach(origQuestion => { questionMap.set(origQuestion.id, origQuestion); }); const tmpQuestions = []; questionIds.forEach(questionId => { if (questionMap.has(questionId)) { const question = questionMap.get(questionId); tmpQuestions.push(question); } });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
Map

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 benchmark and its test cases.

**Benchmark Overview**

MeasureThat.net is a website where users can create and run JavaScript microbenchmarks to compare different approaches to solving a specific problem. In this case, we're comparing two methods for filtering questions based on their IDs: using `Array.prototype.findIndex()` and using a `Map` data structure.

**Test Cases**

There are two test cases:

1. **findIndex**: This test case uses the `Array.prototype.findIndex()` method to filter an array of questions based on their IDs.
2. **Map**: This test case uses a `Map` data structure to store the questions and then filters them using the `get()` method.

**Library Used**

In the `Map` test case, we're using the built-in `Map` class in JavaScript, which is part of the ECMAScript standard.

**Special JS Feature or Syntax**

None of the test cases use any special JavaScript features or syntax that's not widely supported. They only rely on standard JavaScript methods and data structures.

Now, let's discuss the pros and cons of each approach:

**FindIndex**

Pros:

* Simple to implement: `findIndex()` is a well-known method in JavaScript, and its usage is straightforward.
* Fast lookups: `findIndex()` has an average time complexity of O(n), which makes it suitable for large datasets.

Cons:

* Slow for large arrays: For very large arrays, the lookup time can be slow due to the linear search algorithm used by `findIndex()`.
* Creates a temporary index variable: The test case creates a temporary variable `questionIdIndex` to store the result of the `findIndex()` method, which might incur additional overhead.

**Map**

Pros:

* Fast lookups: Using a `Map` data structure allows for fast lookups with an average time complexity of O(1).
* Efficient memory usage: Maps use more efficient memory allocation compared to arrays, especially for large datasets.

Cons:

* Requires extra setup: Creating and populating the `Map` object takes additional code and can be slower than using a simple array lookup.
* Creates an extra data structure: The test case creates an additional `Map` object, which might incur overhead due to memory allocation and garbage collection.

**Other Alternatives**

If you wanted to use other approaches to filter questions based on their IDs, here are some alternatives:

1. **Using a Set**: Similar to the `Map` approach, using a `Set` data structure could provide fast lookups with an average time complexity of O(1).
2. **Using Array.prototype.some() or any()**: Instead of using `findIndex()`, you could use `Array.prototype.some()` or `Array.prototype.any()` methods to filter the array.
3. **Manual Iteration**: For small datasets, you could manually iterate over the array and check each element's ID.

Keep in mind that these alternatives might have different performance characteristics compared to the original test cases.

In conclusion, both approaches have their pros and cons, and the choice of which one to use depends on the specific requirements and constraints of your project.

Related benchmarks:

filter ids with findIndex vs Map access12314 (version: 0)

Comparing performance of: findIndex vs Map

Created: 3 years ago by: Guest

Jump to the latest result

findIndex

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):