Benchmark: array includes vs object key - 1

Script Preparation code:

var obj = (new Array(100000)).fill(null).reduce((prev, newVal, index) => {
  if (index === 55555) {
    prev['sausage'] = 'tst';
    return prev;
  }
 prev[Math.random() + ''] = Math.random() + ''; 
 return prev;
}, {});
var array = Object.keys(obj);

Tests:

Includes
array.includes('sausage')
Object[key]
obj['sausage']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Includes
Object[key]

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Linux; Android 9; STF-L09) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Mobile Safari/537.36

Browser/OS: Chrome Mobile 91 on Android

View result in a separate tab

Test name	Executions per second
Includes	1030.4 Ops/sec
Object[key]	3078006.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore the JavaScript microbenchmark.

**Benchmark Definition**

The provided JSON represents a benchmark definition, which outlines the test case and its requirements. In this case, we have two test cases: "array.includes('sausage')" and "obj['sausage']".

The first test case measures the performance of the `includes()` method on an array. Specifically, it checks if the value `'sausage'` is present in the array.

The second test case measures the performance of accessing an object property using the bracket notation (`obj['sausage']`). This test case creates a large object with 100,000 properties and sets one of them to the value `'tst'`.

**Options Compared**

We have two options being compared:

1. `array.includes('sausage')`
2. `obj['sausage']`

These options are compared in terms of their performance.

**Pros and Cons of Each Approach**

Let's analyze each option:

### 1. `array.includes('sausage')`

Pros:

* This method is concise and easy to read.
* It's a built-in method, so it's likely to be implemented efficiently by the JavaScript engine.

Cons:

* The performance might suffer if the array is very large, since the algorithm has to scan through the entire array to find the value.
* The `includes()` method may not be optimized for this specific use case, which could lead to slower performance compared to a custom solution.

### 2. `obj['sausage']`

Pros:

* This approach allows direct access to the desired property without scanning the object's properties.
* It might be faster when dealing with large objects, since it only accesses a single property.

Cons:

* This method requires creating and populating the entire object, which can lead to slower performance for very large arrays.
* The syntax is more verbose than using `includes()`, which could make the code harder to read.

**Special Consideration: Object Property Access**

In this benchmark, we're accessing an object property using the bracket notation (`obj['sausage']`). This is a valid way to access properties in JavaScript. However, if you're only interested in checking if a value exists within an array, `includes()` would be a better choice.

**Other Alternatives**

If you wanted to explore other alternatives, here are a few options:

* Using the `for...in` loop or `forEach` method to iterate through the object's properties.
* Using the `in` operator with the `hasOwnProperty()` method to check if a property exists on an object.
* Creating a custom function using JavaScript's `Function.prototype.apply()` or `Function.prototype.call()`, which would allow you to pass in the array and value as arguments.

Keep in mind that these alternatives might not be as efficient or readable as the built-in methods, but they could provide more flexibility for certain use cases.

Related benchmarks:

array includes vs object key - 1 (version: 0)

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

Comparing performance of: Includes vs Object[key]

Created: 3 years ago by: Guest

Jump to the latest result

Includes

Object[key]

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):