Benchmark: array indexOf vs includes vs some vs filter

Script Preparation code:

var array = ['banana', 'sausage', 'jesus']

Tests:

IndexOf
array.indexOf('sausage') !== 1
Includes
array.includes('sausage')
some
array.some(v => v === 'sausage')
filter
!!array.filter(v=> v === 'sausage')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IndexOf
Includes
some
filter

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
IndexOf	17227610.0 Ops/sec
Includes	19075062.0 Ops/sec
some	17091234.0 Ops/sec
filter	13044925.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

The provided JSON represents a benchmark that compares four different approaches to find if an array contains a specific value: `array.indexOf()`, `array.includes()`, `array.some()`, and `array.filter()`.

**Benchmark Comparison**

These four methods are used to determine if a certain value exists in the array. Here's what each method does:

*   `array.indexOf(value)`: This method returns the index of the first occurrence of the specified value in the array. If the value is not found, it returns -1.
*   `array.includes(value)`: This method checks if the specified value exists in the array and returns a boolean indicating its presence.
*   `array.some(callbackFunction)`: This method executes the callback function for each element of the array. It immediately returns true as soon as any element passes the test, which can be useful when you only need to find one occurrence of the value.
*   `array.filter(callbackFunction)`: This method creates a new array with all elements that pass the test implemented by the provided callback function.

**Options Compared**

The benchmark compares these four methods' performance across different scenarios. The "Benchmark Definition" field in each test case specifies the exact operation being measured:

*   `array.indexOf('sausage') !== 1`
*   `array.includes('sausage')`
*   `array.some(v => v === 'sausage')`
*   `!!array.filter(v=> v === 'sausage')`

Each method is compared in terms of its speed, which is measured as the number of executions per second.

**Pros and Cons**

Here's a brief overview of each approach:

*   **IndexOf**: This method returns the index of the first occurrence of the value. If the value is not found, it returns -1. The main advantage is that it provides direct access to the element's position in the array. However, this can be slow for large arrays because it requires searching the entire array.
*   **Includes**: This method checks if the specified value exists in the array and returns a boolean indicating its presence. It's generally faster than `indexOf` because it doesn't require searching for an index but rather simply checks if the value is present. However, some older browsers might not support this method, so it may not be suitable for cross-browser compatibility.
*   **Some**: This method executes the callback function for each element of the array and immediately returns true as soon as any element passes the test. It's useful when you only need to find one occurrence of the value but can be slow if all elements pass the test because it requires iterating over the entire array.
*   **Filter**: This method creates a new array with all elements that pass the test implemented by the provided callback function. While this method is often used for data transformations, finding a single element in an array might be slower than using `indexOf` or `includes`.

**Library**

There are no external libraries mentioned in the benchmark definition.

However, it's worth noting that some modern JavaScript implementations like ECMAScript 2022 (ES2022) include more efficient methods like `Find` and `FindIndex`, which can replace some of these array methods for finding specific values.

**Special JS Features or Syntax**

None are explicitly mentioned in the benchmark definition. However, it's always a good idea to be aware that certain features might affect performance, such as:

*   **Arrow functions**: While arrow functions can simplify code and improve readability, they may incur a slight performance penalty due to the creation of new function objects.
*   **Async/await**: When used with asynchronous operations, async/await can introduce overhead due to the need for event loop management.

**Alternatives**

If you're looking for alternatives or ways to optimize array search performance in JavaScript:

1.  **Use `Set` data structures**: If your use case involves storing and searching a collection of unique values (e.g., IDs, usernames), consider using a `Set`. This can provide faster lookup times than traditional arrays.
2.  **Optimize for sparse arrays**: When working with large arrays containing many null or undefined elements, it might be beneficial to create a view into the array that ignores these holes. This approach avoids unnecessary computations and comparisons.
3.  **Use `findIndex` instead of `indexOf`**: In modern browsers, use `FindIndex` (ECMAScript 2017) for its performance benefits over traditional `indexOf`.
4.  **Utilize native browser methods**: Certain browsers provide optimized array search methods like `Array.prototype.find()` and `Array.prototype.findIndex()`. These can offer better performance than traditional JavaScript implementations.
5.  **Leverage SIMD instructions**: When working with numeric arrays, consider using SIMD (Single Instruction, Multiple Data) instructions to perform operations on multiple elements simultaneously. This is particularly effective for large datasets.

By understanding the strengths and weaknesses of each method, you can make informed decisions about which approach best suits your performance-critical use cases.

Related benchmarks:

array indexOf vs includes vs some vs filter (version: 0)

performance comparison of ways to find if an array contains a value

Comparing performance of: IndexOf vs Includes vs some vs filter

Created: one year ago by: Guest

Jump to the latest result

IndexOf

Includes

some

filter

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):