Benchmark: findIndex vs forEach RSE

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);
ForEach
arr.forEach((value) => { if (value.id === foo) { return; } });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
ForEach

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 11 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Linux

View result in a separate tab

Test name	Executions per second
findIndex	56689.6 Ops/sec
ForEach	148997.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition:**

The benchmark is comparing two approaches to find an element in an array:

1. `arr.findIndex((itm) => itm.id === foo);`
2. `arr.forEach((value) => {\r\n  if (value.id === foo) {\r\n    return;\r\n  }\r\n});`

**What's being tested:**

The benchmark is measuring the performance difference between using `findIndex` and a manual loop (`forEach`) to find an element in an array.

**Options compared:**

Two options are being compared:

1. **`findIndex`**: A built-in Array method that returns the index of the first element that satisfies the provided condition.
2. **Manual loop (`forEach`)**: A traditional approach using a `forEach` loop to iterate through the array and return as soon as the desired element is found.

**Pros and Cons of each approach:**

1. **`findIndex`**:
	* Pros:
		+ Efficient, as it only iterates through the array once.
		+ Returns the index directly, making it easier to handle results.
	* Cons:
		+ May not work as expected if the array is empty or contains no elements that match the condition.
2. **Manual loop (`forEach`)**:
	* Pros:
		+ Works for any array size and content.
		+ Can be more intuitive for developers who are familiar with loops.
	* Cons:
		+ Less efficient than `findIndex`, as it requires iterating through the entire array.

**Library/Language features:**

There are no specific libraries or language features being tested in this benchmark. However, it's worth noting that the use of the `forEach` loop is a fundamental concept in JavaScript and other languages with similar syntax.

**Special JS feature/syntax:**

None mentioned in the provided JSON.

**Other considerations:**

When deciding between these two approaches, consider the following:

* Use `findIndex` when:
	+ You need to find an element that satisfies a specific condition.
	+ Performance is critical, and you want to avoid unnecessary iterations through the array.
* Use a manual loop (`forEach`) when:
	+ You're working with arrays of varying sizes or content.
	+ You prefer a more traditional approach to iterating through arrays.

**Alternatives:**

Other alternatives for finding an element in an array include:

1. `indexOf()`: Similar to `findIndex`, but returns -1 if no element is found.
2. `includes()`: A newer method that checks if an element exists within the array without returning its index.
3. Using a third-party library like Lodash's `some()` or `find()` methods.

Keep in mind that these alternatives may have their own pros and cons, depending on your specific use case and requirements.

Related benchmarks:

findIndex vs forEach RSE (version: 0)

Comparing performance of: findIndex vs ForEach

Created: 2 years ago by: Guest

Jump to the latest result

findIndex

ForEach

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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