Benchmark: Array.includes() vs Array.indexOf()

Script Preparation code:

var array = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];

Tests:

Array.includes()
var result = array.includes('d');
Array.indexOf()
var result = array.indexOf('d') > -1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes()
Array.indexOf()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36

Browser/OS: Chrome 80 on Windows

View result in a separate tab

Test name	Executions per second
Array.includes()	8836988.0 Ops/sec
Array.indexOf()	7822926.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**What is being tested?**

The benchmark compares the performance of two methods: `array.includes()` and `array.indexOf()`. Both methods are used to search for a specific value ("d") within an array.

**Options compared:**

1. **`array.includes('d')`**: This method checks if the specified value (`'d'`) exists in the array using the `includes()` method. It returns a boolean value indicating whether the value is present or not.
2. **`array.indexOf('d') > -1`**: This method searches for the specified value (`'d'`) in the array and returns its index if found, or `-1` if not found.

**Pros and Cons of each approach:**

* `array.includes('d')`:
	+ Pros: More concise and readable syntax. It's a one-line expression that directly returns a boolean value.
	+ Cons: Might be slower in some cases, as it uses a binary search algorithm under the hood.
* `array.indexOf('d') > -1`:
	+ Pros: Can return the actual index of the found element if needed, and might be faster for large arrays with unique values.
	+ Cons: Requires an additional comparison (`> -1`) to get the boolean result. The syntax is more verbose.

**Library used in the test case:**

None explicitly mentioned, but `array` is a built-in JavaScript array object.

**Special JS feature or syntax:**

There are no specific special features or syntaxes being tested in this benchmark. However, it's worth noting that both methods rely on the JavaScript engine's implementation of arrays and the `includes()` method.

**Other alternatives:**

For searching for values in an array, other methods might include:

* Using a `for` loop to iterate through the array.
* Using the `some()` method, which returns `true` if at least one element matches the condition.
* Using the `findIndex()` method, which returns the index of the first element that matches the condition.

Keep in mind that these alternatives might have different performance characteristics and use cases compared to the `includes()` and `indexOf()` methods.

Related benchmarks:

Array.includes() vs Array.indexOf() (version: 0)

Comparing performance of: Array.includes() vs Array.indexOf()

Created: 5 years ago by: Guest

Jump to the latest result

Array.includes()

Array.indexOf()

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):