Benchmark: Filter vs FindIndex splice

Script Preparation code:

var arr = [...Array(1000)].map((e,i) => i+1);

Tests:

Array.filter
var tempResult = arr.filter((e,i) => e===800)
Array.findIndex
var x = arr.findIndex((e,i) => e===800) var tempResult = arr.splice(x, 1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.filter
Array.findIndex

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/114.0.0.0 Safari/537.36 Edg/114.0.1823.51

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
Array.filter	705752.0 Ops/sec
Array.findIndex	4627016.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the provided benchmark.

**Overview**

The benchmark measures the performance of two JavaScript methods: `Array.prototype.filter()` and `Array.prototype.findIndex()`. Both methods are used to find specific elements in an array, but they operate differently.

**Options Compared**

There are two options being compared:

1. **`Array.prototype.filter()`**: This method creates a new array with all elements that pass the test implemented by the provided function.
2. **`Array.prototype.findIndex()`**: This method returns the index of the first element in the array that satisfies the testing function.

**Pros and Cons**

*   **`Array.prototype.filter()`**:
    *   Pros: Efficient for finding multiple matching elements, relatively simple to understand and implement, works well with smaller arrays.
    *   Cons: Creates a new array, which can be memory-intensive for large datasets. Can be slower for very large arrays due to the overhead of creating a new array.
*   **`Array.prototype.findIndex()`**:
    *   Pros: Returns the index directly, avoiding unnecessary creation of new data structures. Suitable for scenarios where only one matching element is required.
    *   Cons: Returns `NaN` if no elements match, which can be problematic in some cases. Can be slower due to the need to perform a search within the array.

**Library and Special JS Feature**

Neither of the methods relies on a specific JavaScript library or feature that's not inherent to the language itself.

**Special JS Syntax**

The benchmark doesn't use any special JavaScript syntax, but it does utilize the fact that arrays in JavaScript are 0-indexed, meaning that the first element is at index 0.

**Other Alternatives**

If `Array.prototype.filter()` and `Array.prototype.findIndex()` aren't sufficient for your needs, you might consider these alternative approaches:

*   **Using `Array.prototype.forEach()`**: Instead of using `filter()` or `findIndex()`, you could use a simple loop with `forEach()` to iterate over the array and find the desired elements. This approach is more straightforward but also less efficient due to the overhead of looping.
*   **Using `reduce()`**: You can use the `reduce()` method in conjunction with another method (like `Array.prototype.map()`) or directly to filter and transform arrays in a concise way.

Keep in mind that each of these alternatives has its trade-offs in terms of readability, memory usage, and performance.

Related benchmarks:

Filter vs FindIndex splice (version: 0)

Comparing performance of: Array.filter vs Array.findIndex

Created: one year ago by: Guest

Jump to the latest result

Array.filter

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):