Benchmark: array.indexOf vs array.includes vs array.some vs equality

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']
var value = 'sausage';

Tests:

array.indexOf
array.indexOf(value) !== 1
array.includes
array.includes(value)
array.some
array.some(v => v === value)
equality
'banana' === value || 'sausage' === value || jesus === 'value'

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.indexOf
array.includes
array.some
equality

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Mac OS X 10.15.7

View result in a separate tab

equality

16.6M/s

array.includes

15.6M/s

array.indexOf

15.5M/s

array.some

11.0M/s

View exact numbers

Test name	Executions per second
✓ equality	16,639,557 Ops/sec
array.includes	15,603,358 Ops/sec
array.indexOf	15,460,332 Ops/sec
array.some	10,950,476 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

The `MeasureThat.net` website is used to create and run JavaScript microbenchmarks. The current benchmark compares the performance of different methods to find if an array contains a value: `array.indexOf`, `array.includes`, `array.some`, and equality checks using string comparisons (`'banana' === value || 'sausage' === value || jesus === 'value'`).

**Options Compared**

1. **array.indexOf**: This method returns the index of the first occurrence of the specified value in the array, or -1 if it's not found.
2. **array.includes**: This method checks if the array includes the specified value and returns a boolean result (true or false).
3. **array.some**: This method tests whether at least one element in the array passes a provided test.
4. **Equality Checks** (`'banana' === value || 'sausage' === value || jesus === 'value'`): These are simple string comparisons using the `===` operator.

**Pros and Cons of Each Approach**

1. **array.indexOf**:
	* Pros: Fast for finding a specific element in an array, returns the index of the found element.
	* Cons: Returns -1 if not found, can be slower than other methods for very large arrays.
2. **array.includes**:
	* Pros: Simple and efficient way to check if an element is present in an array, returns a boolean result.
	* Cons: May be slower than `indexOf` or equality checks for very large arrays.
3. **array.some**:
	* Pros: Allows testing multiple conditions on each array element, can be faster than individual comparisons.
	* Cons: Returns a boolean result indicating whether at least one element passes the test, may not be suitable for finding a specific element.
4. **Equality Checks** (`'banana' === value || 'sausage' === value || jesus === 'value'`):
	* Pros: Simple and easy to understand, can be faster than array methods for very small arrays.
	* Cons: May be slower than array methods for large arrays, may not handle null or undefined values well.

**Library Used**

The benchmark uses the `lodash.js` library, specifically the `lodash.some()` function. The script preparation code includes a line to load this library from a CDN.

**Special JS Features/Syntax**

There is no specific JavaScript feature or syntax mentioned in the benchmark that requires special attention. All test cases use standard JavaScript methods and operators.

**Other Alternatives**

For finding if an array contains a value, other alternatives could include:

* Using `Array.prototype.includes()` method (not available in older browsers)
* Implementing a custom binary search algorithm
* Using a data structure like a hash table or set to quickly look up values

However, for most use cases, the methods compared in this benchmark (`array.indexOf`, `array.includes`, and equality checks) are sufficient.

array.indexOf vs array.includes vs array.some vs equality (version: 0)

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

Comparing performance of: `array.indexOf vs array.includes vs array.some vs equality`

Created: 2 years ago by: Guest

Go to the latest result

array.indexOf

array.includes

array.some

equality

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

array.indexOf vs array.includes vs array.some vs equality (version: 0)

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

Comparing performance of: array.indexOf vs array.includes vs array.some vs equality

Created: 2 years ago by: Guest

Go to the latest result

array.indexOf

array.includes

array.some

equality

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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Comparing performance of: `array.indexOf vs array.includes vs array.some vs equality`