Benchmark: Object.hasOwn vs Object in vs Object[] vs Array.indexOf vs Array.includes

Script Preparation code:

  var object = {},
      array = [],
      i, test = 1000;
  
  for (i = 0; i < 20; i++) {
   object['something' + i] = true;
   array.push('something' + i);
  }

Tests:

Object.hasOwnProperty
object.hasOwnProperty('something' + test)
Object in
('something' + test) in object
Array.indexOf
array.indexOf('something' + test) !== -1
direct
object['something' + test] === true
Array includes
Object.keys(object).includes('something' + test)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.hasOwnProperty
Object in
Array.indexOf
direct
Array includes

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares the performance of four different ways to check if a property exists in an object:

1. `Object.hasOwnProperty`
2. `(key) in object` (using the "in" operator)
3. `array.indexOf(key) !== -1` (checking if the key is not found at the end of the array)
4. `object[key] === value` (direct access to the property)

**Options Compared**

The benchmark compares these four options because they are all commonly used in JavaScript to check if a property exists, but they may have different performance characteristics.

**Pros and Cons of Each Approach**

1. **`Object.hasOwnProperty`**: This approach is often considered the most efficient and straightforward way to check if a property exists on an object. It's also widely supported by browsers.
	* Pros: Fast, widely supported, easy to read.
	* Cons: May not be as readable for some developers who are used to other approaches.
2. **`(key) in object`**: This approach uses the "in" operator to check if a key exists in an object. It's often considered more concise and expressive than `Object.hasOwnProperty`.
	* Pros: Concise, expressive, works well with objects that have a lot of properties.
	* Cons: May be slower than `Object.hasOwnProperty` due to the overhead of the "in" operator.
3. **`array.indexOf(key) !== -1`**: This approach checks if the key is not found at the end of the array using `indexOf`. It's often used when working with arrays instead of objects.
	* Pros: Fast, widely supported, works well with arrays.
	* Cons: May be slower than `Object.hasOwnProperty` or `(key) in object`, as it requires searching the entire array.
4. **`object[key] === value`**: This approach directly accesses the property using bracket notation. It's often considered a simple and straightforward way to check if a property exists.
	* Pros: Fast, simple, widely supported.
	* Cons: May be slower than `Object.hasOwnProperty` or `(key) in object`, as it requires accessing the property directly.

**Library Used**

There is no explicit library used in this benchmark. However, the "in" operator and bracket notation are built-in JavaScript features that are widely supported by browsers.

**Special JS Features/Syntax**

None of the test cases use any special JavaScript features or syntax beyond what's built into the language.

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/99.0.4844.83 Safari/537.36

Browser/OS: Chrome 99 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.hasOwnProperty	8109391.5 Ops/sec
Object in	6951356.0 Ops/sec
Array.indexOf	9916604.0 Ops/sec
direct	6901056.5 Ops/sec
Array includes	2463506.0 Ops/sec

Related benchmarks:

Object.hasOwn vs Object in vs Object[] vs Array.indexOf vs Array.includes (version: 0)

Comparing performance of: Object.hasOwnProperty vs Object in vs Array.indexOf vs direct vs Array includes

Created: 2 years ago by: Guest

Jump to the latest result

Object.hasOwnProperty

Object in

Array.indexOf

direct

Array includes

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):