Benchmark: Find object in array

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var users = [
  { 'user': 'joey',  'age': 28 },
  { 'user': 'ross',    'age': 31 },
  { 'user': 'chandler', 'age': 30 },
  { 'user': 'jessika', 'age': 21 },
  { 'user': 'amanda', 'age': 17 }
]

Tests:

findIndex
users.findIndex(u => u.age === 17)
lodash
_.findIndex(users, u => u.age === 17)
for loop
for (var i = 0; i < users.length; i++) { if (users[i].age === 17) { return i } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
lodash
for loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Browser/OS: Chrome 90 on Windows 7

View result in a separate tab

Test name	Executions per second
findIndex	2553955.2 Ops/sec
lodash	850448.4 Ops/sec
for loop	287819.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the provided JSON benchmark data.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmarking test suite, where users can create and run benchmarks to measure the performance of different approaches for finding an object in an array. The benchmark consists of three test cases:

1. Using the built-in `findIndex` method.
2. Using the Lodash library's `findIndex` function.
3. Using a traditional `for` loop.

**Test Cases**

Let's break down each test case and explain what is being tested:

### 1. findIndex

This test case measures the performance of using the built-in `findIndex` method in JavaScript. The `findIndex` method returns the index of the first element that satisfies the provided condition (in this case, finding an object with an age of 17). The benchmark script prepares an array of objects and then uses `findIndex` to find the desired object.

**Pros:**

* Native implementation, likely optimized for performance.
* Simple and concise syntax.

**Cons:**

* May have slower performance compared to other approaches due to its inherent nature.
* Limited control over optimization flags (e.g., `-O3`, `-Os`).

### 2. Lodash

This test case measures the performance of using the Lodash library's `findIndex` function. The benchmark script includes a CDN link to the Lodash library and then uses the `_.findIndex` function from Lodash to find the desired object.

**Pros:**

* Well-optimized and tested implementation.
* Provides more control over optimization flags (e.g., `_.partial`, `_with`) through Lodash's API.

**Cons:**

* Additional dependency on Lodash library, which may introduce overhead.
* May have slower performance compared to native `findIndex` due to the additional layer of indirection.

### 3. For Loop

This test case measures the performance of using a traditional `for` loop to find an object in the array. The benchmark script prepares an array of objects and then uses a `for` loop to iterate over the elements, checking each one's age until finding the desired value.

**Pros:**

* Provides direct control over iteration logic.
* May have better performance due to optimized native code generation.

**Cons:**

* More verbose syntax compared to other approaches.
* Requires explicit indexing and looping logic, which can be error-prone.

**Library: Lodash**

In this benchmark, the `findIndex` function from Lodash is used. Lodash is a popular JavaScript library that provides utility functions for common tasks, such as array manipulation, string manipulation, and more. The `_.findIndex` function is specifically designed to find the index of the first element in an array that satisfies a given condition.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark beyond what's already discussed. However, it's worth noting that some modern JavaScript engines (e.g., V8) have implemented various optimization flags and options to improve performance. For example, `-O3` can enable more aggressive optimization, while `-Os` can optimize for size instead of speed.

**Alternatives**

Other alternatives for finding an object in an array include:

* Using the `some()` method with a callback function.
* Using `every()` method with a callback function (although this is typically used to check if all elements satisfy a condition).
* Using other libraries or frameworks that provide similar functionality, such as Ramda.

Overall, the choice of approach depends on the specific use case, personal preference, and performance requirements.

Related benchmarks:

Find object in array (version: 0)

Comparing performance of: findIndex vs lodash vs for loop

Created: 3 years ago by: Guest

Jump to the latest result

findIndex

lodash

for loop

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):