Benchmark: findindex vs map && indexOf

Script Preparation code:

var arr = new Array(15000);
arr.fill({ id: 0 });
arr = arr.map((el, idx) => el.id = idx);
var foo = Math.floor(Math.random() * 15000);

Tests:

findIndex
const userIdx = arr.findIndex(user => user.id === foo);
map && indexOf
const userIdx = arr.map(user => user.id).indexOf(foo);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
map && indexOf

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Browser/OS: Chrome 90 on Windows

View result in a separate tab

Test name	Executions per second
findIndex	622.0 Ops/sec
map && indexOf	7642.3 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 compares two approaches to find an element in an array: `findIndex` and `map && indexOf`. The test case creates an array of 15,000 elements with a unique `id` property, fills it with random values, and then searches for a specific `id` value using both methods.

**Options Compared**

The two options being compared are:

1. **`findIndex`**: This method returns the index of the first element in the array that satisfies the provided condition (in this case, `user.id === foo`). It's a linear search algorithm.
2. **`map && indexOf`**: This approach uses the `map()` method to create a new array with transformed elements, and then uses the `indexOf()` method to find the index of the desired value in the resulting array.

**Pros and Cons**

1. **`findIndex`**:
	* Pros: Simple, efficient for large arrays.
	* Cons: Linear search can be slow for small arrays or when the condition is not met at all.
2. **`map && indexOf`**:
	* Pros: Can be faster than `findIndex` for large arrays because it avoids the need to check each element multiple times.
	* Cons: Creates a new array, which can consume more memory; uses two method calls, which might incur additional overhead.

**Library and Special Features**

There is no explicit library mentioned in the benchmark. However, the `map()` and `indexOf()` methods are part of the built-in JavaScript API.

The test case does not use any special JavaScript features or syntax beyond what's considered standard.

**Other Alternatives**

In addition to the two options being compared, other approaches to find an element in an array might include:

1. **`forEach()`**: Iterates over each element and checks if it matches the condition.
2. **`filter()`**: Creates a new array with elements that satisfy the condition, but does not provide an index of the matching element.
3. **`reduce()`**: Accumulates values while iterating over the array, which might be useful in certain scenarios.

The choice of approach depends on the specific requirements and constraints of the application.

Related benchmarks:

findindex vs map && indexOf (version: 0)

Comparing performance of: findIndex vs map && indexOf

Created: 3 years ago by: Guest

Jump to the latest result

findIndex

map && indexOf

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):