Benchmark: Some vs. indexOf

Script Preparation code:

var arr = [];
arr.push('A');
arr.push('B');
arr.push('C');
arr.push('D');

Tests:

Array.some
var tempResult = arr.some(v => v === 'D');
Array.indexOf
var tempResult = arr.indexOf('D') > -1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.some
Array.indexOf

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the provided benchmark.

**What is tested?**

The benchmark compares two JavaScript methods: `some()` and `indexOf()`. Both methods are used to test if a specific element exists in an array.

**Options compared:**

* `some()`: This method returns `true` as soon as it finds an element that satisfies the provided condition (in this case, `v === 'D'`). If no such element is found after iterating through the entire array, it returns `false`.
* `indexOf()`: This method returns the index of the first occurrence of the specified element (`'D'` in this case). If the element is not found, it returns `-1`.

**Pros and Cons:**

* `some()`:
	+ Pros:
		- More concise code
		- Can be faster if the array is large and most elements don't match the condition
		- Less memory usage since it only needs to iterate through a subset of elements
	+ Cons:
		- May not be as readable, especially for those unfamiliar with this method
		- If no elements match the condition, it returns `false`, which might be unexpected behavior
* `indexOf()`:
	+ Pros:
		- More explicit and readable code
		- Returns a specific value (-1) to indicate non-existence, making it more predictable
	+ Cons:
		- May be slower for large arrays since it needs to iterate through the entire array
		- Requires more memory usage since it needs to store the indices of all elements

**Library and purpose:**

None mentioned in this benchmark.

**Special JavaScript feature or syntax:**

* `some()` is a modern JavaScript method introduced in ECMAScript 2015 (ES6). It's designed to improve performance by allowing iteration stops early.
* The arrow function `v => v === 'D'` is also a modern JavaScript feature, known as an "arrow function" or "lambda expression".

**Other considerations:**

The benchmark only tests these two methods on the same array. In a real-world scenario, you might want to test both methods on different arrays, using different data distributions, and considering other factors like performance under various conditions.

**Alternatives:**

* For `some()`, you can also use `every()` in reverse, i.e., `arr.some(v => !v.includes('D'))` (note the negation).
* For `indexOf()`, you might want to consider using `findIndex()` which is similar but returns the index of the first matching element or `-1` if no match is found.
* Another approach could be using a simple loop and checking each element individually.

Keep in mind that these alternatives are not necessarily faster, more efficient, or more readable than the original methods. The choice ultimately depends on your specific use case and performance requirements.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Linux; Android 10; GM1913) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.79 Mobile Safari/537.36

Browser/OS: Chrome Mobile 79 on Android

View result in a separate tab

Test name	Executions per second
Array.some	8436380.0 Ops/sec
Array.indexOf	8324642.0 Ops/sec

Related benchmarks:

Some vs. indexOf (version: 0)

Comparing performance of: Array.some vs Array.indexOf

Created: 4 years ago by: Guest

Jump to the latest result

Array.some

Array.indexOf

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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