Benchmark: Array includes vs Object key lookup vs Object hasOwnProperty

Script Preparation code:

var a = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten'];
var b = Object.freeze({
    'one': true,
    'two': true,
    'three': true,
    'four': true,
    'five': true,
    'six': true,
    'seven': true,
    'eight': true,
    'nine': true,
    'ten': true
});

Tests:

Array includes
return a.includes('eight')
Object key lookup
return b['eight'] === true
Object hasOwnProperty
return b.hasOwnProperty('eight')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array includes
Object key lookup
Object hasOwnProperty

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36 Edg/115.0.1901.203

Browser/OS: Chrome 115 on Windows

View result in a separate tab

Test name	Executions per second
Array includes	13081687.0 Ops/sec
Object key lookup	13609794.0 Ops/sec
Object hasOwnProperty	12592347.0 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 the provided JSON.

**Benchmark Definition**
The benchmark compares the performance of three different approaches:

1. **Array.prototype.includes()**: This method checks if a specified value exists in an array. In this case, it searches for the string "eight" in the array `a`.
2. **Object key lookup**: This approach uses the bracket notation (`b['eight'] === true`) to access a property in an object `b`. The property is set to the value `true`, and we're checking if its existence matches what `Array.prototype.includes()` would return.
3. **Object.prototype.hasOwnProperty()**: Similar to object key lookup, this method checks if an object has a specific property with the given name (`b.hasOwnProperty('eight')`). However, it's more efficient because it doesn't need to check all properties of the object.

**Options Comparison**
The pros and cons of each approach are:

* **Array.prototype.includes()**: Pros: widely supported, easy to use. Cons: can be slow for very large arrays or when searching for a specific value in a large array.
* **Object key lookup**: Pros: efficient for objects with many properties, as it only checks the requested property. Cons: requires knowledge of bracket notation and object property access.
* **Object.prototype.hasOwnProperty()**: Pros: faster than object key lookup, especially for smaller objects or when searching for an exact match. Cons: not all browsers support this method, and its usage can be more verbose.

**Library Usage**
In the provided code, `Object.freeze()` is used to make the object `b` immutable. This is a utility function in JavaScript that converts an object into an immutable object.

**Special JS Feature or Syntax**
There are no special features or syntaxes being tested here, as all methods are standard ECMAScript methods.

**Other Considerations**

* The benchmark uses Chrome 115, Windows 10, and a desktop device. This might limit the results to this specific browser and platform.
* The benchmark is run on the same machine, which could lead to inconsistent results if the environment changes (e.g., upgrading the OS or hardware).
* The benchmark does not consider other factors that might affect performance, such as array size, object complexity, or concurrent execution.

**Alternative Benchmarks**
If you wanted to explore alternative approaches, you might consider:

* Using `Array.prototype.indexOf()` instead of `includes()`.
* Implementing a custom search function for arrays using binary search.
* Comparing the performance of different object implementations (e.g., `Object.create()`, `Object.fromEntries()`) or data structures (e.g., `Set` vs. `Map`).

Related benchmarks:

Array includes vs Object key lookup vs Object hasOwnProperty (version: 0)

Compares performance of Array.prototype.includes() vs Object key lookup vs Object.prototype.hasOwnProperty()

Comparing performance of: Array includes vs Object key lookup vs Object hasOwnProperty

Created: one year ago by: Guest

Jump to the latest result

Array includes

Object key lookup

Object hasOwnProperty

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):