Benchmark: find vs findIndex (Array prototype methods) stop at first found

Script Preparation code:

var arr = [];
var i = 0;

while (i <= 1E5) arr[i] = i++;

Tests:

Array.prototype.find
const item = arr.find(item => item == 15);
Array.prototype.findIndex
const index = arr.findIndex(item => item == 15);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.find
Array.prototype.findIndex

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.prototype.find	103849912.0 Ops/sec
Array.prototype.findIndex	107191480.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its options.

**Benchmark Definition**

The benchmark is designed to compare two methods for finding the first element in an array that matches a specific condition: `find` and `findIndex`. Both methods are part of the Array prototype.

**Options Compared**

The main difference between `find` and `findIndex` lies in their behavior when no elements match the condition:

*   `find`: Returns `undefined` if no element is found. It stops searching as soon as it finds a match.
*   `findIndex`: Returns `-1` if no element is found. It continues searching until it finds an element or reaches the end of the array.

**Pros and Cons**

*   **Efficiency**: If you only need to find one element, `find` might be slightly faster because it stops searching as soon as it finds a match.
*   **Safety**: `findIndex` is safer because it doesn't rely on returning `undefined`, which can cause issues if you're not expecting an empty array. However, if you know that the array will always have at least one element, `find` might be faster.

**Library Used**

In this benchmark, no external library is used.

**Special JavaScript Features/Syntax**

This benchmark doesn't use any special JavaScript features or syntax beyond what's available in modern browsers.

**Other Alternatives**

If you need to find the first element in an array that matches a condition, there are other alternatives:

*   **Using a for loop**: You can iterate over the array using a `for` loop and return as soon as you find a match. This approach is similar to `find`, but it's not optimized like the built-in methods.
*   **Using `some()` or `every()`**: While these methods don't directly help with finding the first element, they can be used in conjunction with another method to achieve a similar result.

Overall, both `find` and `findIndex` are suitable for this use case. If you need to find one specific element and don't mind potentially getting `undefined`, `find` might be faster. However, if you're working with arrays that may not have any matches or want the safety net of returning a numeric value regardless of whether an element is found, `findIndex` is a better choice.

As for the benchmark results provided, they show the execution speeds for both methods on Opera 82 running on Windows. The browser returns more executions per second with `findIndex`, indicating that it's faster in this specific test case.

Related benchmarks:

find vs findIndex (Array prototype methods) stop at first found (version: 0)

Measuring which is faster

Comparing performance of: Array.prototype.find vs Array.prototype.findIndex

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.find

Array.prototype.findIndex

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):