Benchmark: array indexOf vs includes vs some vs for loop

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var array = ['banana', 'sausage', 'jesus', 'foo', 'bar', 'baz']
var len = array.length

Tests:

IndexOf
array.indexOf('sausage') !== 1
Includes
array.includes('sausage')
some
array.some(v => v === 'sausage')
for loop
for (let i = 0; i < len; i++) { if (array[i] === 'sausage') break; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IndexOf
Includes
some
for loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Android 13; Mobile; rv:147.0) Gecko/147.0 Firefox/147.0

Browser/OS: Firefox Mobile 147 on Android

View result in a separate tab

Test name	Executions per second
IndexOf	24478498.0 Ops/sec
Includes	24066540.0 Ops/sec
some	217715680.0 Ops/sec
for loop	206684896.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The benchmark, titled "array indexOf vs includes vs some vs for loop," tests the performance of four different approaches to check if an array contains a specific value:

1. `indexOf()`
2. `includes()`
3. `some()` with a callback function
4. A traditional `for` loop

**Approach 1: `indexOf()`**

`indexOf()` returns the index of the first occurrence of a specified element in an array. If no such element exists, it returns `-1`.

Pros:

* Simple and straightforward
* Native implementation in most browsers

Cons:

* Returns an index value, which might not be desirable if you're only interested in the presence or absence of the element
* Can be slower than other methods for large arrays

**Approach 2: `includes()`**

`includes()` returns a boolean indicating whether an array contains a specified element.

Pros:

* Simple and straightforward
* Returns a boolean value, which is more convenient than an index
* Faster than `indexOf()` for large arrays (thanks to its native implementation)

Cons:

* Not supported in older browsers

**Approach 3: `some()` with a callback function**

`som()` returns a boolean indicating whether at least one element of an array satisfies the provided testing function.

Pros:

* More flexible, as it allows you to perform more complex checks
* Can be used for arrays of arbitrary types

Cons:

* Requires creating and passing a callback function, which can add overhead
* Less straightforward than other methods

**Approach 4: Traditional `for` loop**

A traditional `for` loop iterates over the array elements, checking each one against the target value.

Pros:

* Highly customizable, as you can modify the loop to suit your needs
* Can be more efficient for small arrays or when exact indexing is required

Cons:

* More verbose and error-prone than other methods
* Requires manual iteration, which can lead to off-by-one errors

**Library: Lodash**

The benchmark uses a modified version of Lodash's `lodash.min.js` library. Lodash provides various utility functions, including `indexOf()` and `includes()`, which are used in the benchmark.

Pros:

* Simplifies code and reduces overhead for common tasks
* Provides consistent behavior across browsers

Cons:

* Adds dependency on an external library
* May not be suitable for all use cases due to its size and complexity

**Special JS Feature/Syntax: None**

This benchmark does not utilize any special JavaScript features or syntax.

**Other Alternatives**

If you're looking for alternative approaches, consider the following:

* `filter()`: Returns a new array containing only elements that pass the test implemented by the provided function.
* `every()`: Returns a boolean indicating whether all elements of an array satisfy the testing function.
* `reduce()`: Applies a reduction function to each element in an array and returns a single output value.

Keep in mind that these alternatives might not be directly comparable to the original methods tested in this benchmark.

Related benchmarks:

array indexOf vs includes vs some vs for loop (version: 0)

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

Comparing performance of: IndexOf vs Includes vs some vs for loop

Created: one year ago by: Guest

Jump to the latest result

IndexOf

Includes

some

for loop

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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