Benchmark: Object arrays: findIndex vs for loop vs some

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
arr.findIndex((itm) => itm.id === foo);
for loop
for (let i = 0; i < arr.length; i++) { if (arr[i].id === foo) break; }
some
arr.some((itm) => itm.id === foo);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
for loop
some

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
findIndex	1933.5 Ops/sec
for loop	400.5 Ops/sec
some	906.5 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 its components.

**Benchmark Description**

The benchmark compares three approaches to find an element in an array:

1. `arr.findIndex((itm) => itm.id === foo)` - uses the `findIndex` method
2. `for (let i = 0; i < arr.length; i++) {\r\n  if (arr[i].id === foo) break;\r\n}` - uses a traditional for loop
3. `arr.some((itm) => itm.id === foo)` - uses the `some` method

**Options Compared**

* `findIndex`: uses the `findIndex` method, which returns the index of the first element that satisfies the condition.
* `for loop`: uses a traditional for loop to iterate through the array and check each element.
* `some`: uses the `some` method, which returns true if at least one element in the array satisfies the condition.

**Pros and Cons**

* `findIndex`:
	+ Pros: efficient, as it stops iterating as soon as the first match is found.
	+ Cons: may not be suitable for arrays with no matches (returns -1), and can be slower than other approaches for very large arrays.
* `for loop`:
	+ Pros: straightforward to implement, and allows for early exit if a match is found.
	+ Cons: can be slow for large arrays due to the overhead of iteration and branching.
* `some`:
	+ Pros: similar to `findIndex`, but returns true instead of an index. Can be faster in some cases due to optimized implementation.
	+ Cons: may not be suitable for finding a single match, as it will return true if any element matches.

**Library/Functionality**

None of the benchmarked approaches use external libraries or functions.

**Special JS Feature/Syntax**

There is no special JavaScript feature or syntax used in this benchmark. All approaches are standard and well-supported by most browsers.

**Alternatives**

Other alternatives to compare could be:

* Using `includes()` method instead of `findIndex` or `some`
* Using a custom iterative approach with caching or early exit conditions
* Comparing the performance of other array methods, such as `filter()`, `map()`, or `reduce()`

These alternatives would require additional benchmark setup and results, but could provide further insights into optimal approaches for specific use cases.

Related benchmarks:

Object arrays: findIndex vs for loop vs some (version: 0)

Testing finding an object array via findIndex or by using a for loop or by using some

Comparing performance of: findIndex vs for loop vs some

Created: one year ago by: Guest

Jump to the latest result

findIndex

for loop

some

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):