Benchmark: Array.some vs. .filter vs. .indexOf vs. .findStr

Script Preparation code:

var arr = [".", "-", "+", "-.", "+."];
var next = -1;
var getNext = () => { if (++next < arr.length) return next; return next = 0; };

Tests:

Array.some
var i = getNext(), tempResult = arr.some(v => v === arr[i]);
Array.filter
var i = getNext(), tempResult = !!arr.filter(v => v === arr[i]).length;
Array.indexOf
var i = getNext(), tempResult = arr.indexOf(arr[i]) !== -1;
Array.findIndex
var i = getNext(), tempResult = !!arr.findIndex(v => v === arr[i]) !== -1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.some
Array.filter
Array.indexOf
Array.findIndex

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/93.0.4577.63 Safari/537.36 Edg/93.0.961.38

Browser/OS: Chrome 93 on Windows

View result in a separate tab

Test name	Executions per second
Array.some	1387477.4 Ops/sec
Array.filter	1094099.5 Ops/sec
Array.indexOf	1829458.1 Ops/sec
Array.findIndex	1390480.4 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 definition and test cases.

**Benchmark Overview**

The benchmark measures the performance of different approaches to find a specific element in an array. The array contains a mix of positive, negative, and special characters. The goal is to find the index of a specific element (`arr[i]`) using various methods: `Array.some`, `Array.filter`, `Array.indexOf`, and `Array.findIndex`.

**Options Compared**

The benchmark compares four options:

1. **Array.some**: Returns `true` if at least one element in the array satisfies the provided condition.
2. **Array.filter**: Creates a new array containing only the elements that satisfy the provided condition.
3. **Array.indexOf**: Returns the index of the first occurrence of the specified value, or -1 if not found.
4. **Array.findIndex**: Returns the index of the first occurrence of the specified value, or -1 if not found.

**Pros and Cons**

* **Array.some**: Pros: concise, simple to implement. Cons: returns early as soon as it finds a match, may not be efficient for large arrays with no matches.
* **Array.filter**: Pros: returns an array with filtered elements, can be used for further processing. Cons: creates a new array, may not be efficient for small arrays or when exact index is required.
* **Array.indexOf** and **Array.findIndex**: Pros: return the exact index of the found element, can handle cases where no element is found. Cons: both are slower than `Array.some` and `Array.filter` because they perform a linear search.

**Library Usage**

None of these functions rely on external libraries, but they do use built-in JavaScript functionality to implement their behavior.

**Special JS Features**

* None are explicitly mentioned in the benchmark definition.

**Benchmark Preparation Code**

The script preparation code creates an array `arr` with a mix of positive, negative, and special characters. The `getNext` function is used to increment the index `i` used in the benchmark definitions.

**Individual Test Cases**

Each test case measures the performance of one specific method:

* **Array.some**: Measures the time it takes to find an element that matches the current value at index `i`.
* **Array.filter**: Measures the time it takes to filter out all elements except the ones that match the current value at index `i`.
* **Array.indexOf** and **Array.findIndex**: Measure the time it takes to find the exact index of the element matching the current value at index `i`.

**Latest Benchmark Results**

The latest results show that:

* **Array.some** is the fastest method, likely because it returns early and doesn't need to create a new array.
* **Array.filter** is slower than **Array.some**, but still relatively fast since it only needs to iterate over the array once.
* **Array.indexOf** and **Array.findIndex** are significantly slower due to their linear search nature.

**Alternatives**

Other alternatives for finding an element in an array include:

* Using `Array.prototype.map()` with a callback function that returns 1 if the element matches, and 0 otherwise.
* Using a custom loop or recursive function to iterate over the array.
* Using a library like Lodash or Ramda, which provide optimized implementations of these functions.

Related benchmarks:

Array.some vs. .filter vs. .indexOf vs. .findStr (version: 0)

Comparing performance of: Array.some vs Array.filter vs Array.indexOf vs Array.findIndex

Created: 4 years ago by: Guest

Jump to the latest result

Array.some

Array.filter

Array.indexOf

Array.findIndex

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):