Benchmark: IndexOf vs Includes in array

Script Preparation code:

var array = ['image/heic', 'image/heif']

Tests:

IndexOf
array.indexOf('image/heic') !== -1
Includes
array.includes('image/heic')

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Includes

134.7M/s

IndexOf

123.6M/s

View exact numbers

✓ Includes: 134,687,984 ops/sec
• IndexOf: 123,618,848 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IndexOf
Includes

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.3 Safari/605.1.15

Browser/OS: Safari 26 on Mac OS X 10.15.7

View result in a separate tab

IndexOf

494.5M/s

Includes

493.2M/s

View exact numbers

Test name	Executions per second
✓ IndexOf	494,545,408 Ops/sec
Includes	493,202,496 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 benchmark and analyze what's being tested.

**Benchmark Overview**

The benchmark is designed to compare the performance of two methods in JavaScript: `indexOf()` and `includes()`. Both methods are used to search for a specific value within an array. The goal is to determine which method is faster, more efficient, or less prone to errors.

**Script Preparation Code**

The script preparation code defines an array with two elements:
```javascript
var array = ['image/heic', 'image/heif'];
```
This array will be used as the search space for both `indexOf()` and `includes()` methods.

**Options Compared**

Two options are being compared:

1. **`array.indexOf('image/heic') !== -1`**: This uses the `indexOf()` method to find the index of a specific value within the array, and then checks if it's not equal to `-1`, indicating that the value was found.
2. **`array.includes('image/heic')`**: This uses the `includes()` method directly, without searching for an index.

**Pros and Cons**

* `indexOf()`:
	+ Pros: Can be more efficient when you need to find the exact index of a value in the array.
	+ Cons: May return `-1` if the value is not found, which can lead to errors if you're expecting a specific result.
* `includes()`: 
	+ Pros: More concise and expressive than using `indexOf()` with a check for `-1`.
	+ Cons: Can be slower for very large arrays, since it needs to search the entire array.

**Library**

There is no explicit library being used in this benchmark. However, both methods are built-in JavaScript functions.

**Special JS Feature/Syntax**

None are explicitly mentioned in this benchmark.

**Other Considerations**

* Both methods have different performance characteristics: `indexOf()` tends to be faster for small arrays, while `includes()` can be slower for very large arrays.
* If you're searching for a specific value that's likely to exist within the array (e.g., a common file extension), using `indexOf()` with a check for `-1` might be a better choice.

**Alternatives**

Other alternatives for string matching in JavaScript include:

* Using a library like Lodash or Ramda, which provide more powerful and flexible string manipulation functions.
* Using regular expressions to search for patterns within strings.
* Using other data structures, such as hash tables or trie data structures, to store and query arrays.

Overall, this benchmark is designed to highlight the differences between two simple yet common JavaScript methods, allowing users to compare performance and choose the best approach for their specific use case.

IndexOf vs Includes in array (version: 0) Benchmark.js

Banana

Comparing performance of: `IndexOf vs Includes`

Created: 5 years ago by: Guest

Go to the latest result

IndexOf

Includes

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

IndexOf vs Includes in array (version: 0) Benchmark.js

Banana

Comparing performance of: IndexOf vs Includes

Created: 5 years ago by: Guest

Go to the latest result

IndexOf

Includes

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

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: `IndexOf vs Includes`