Benchmark: Array.includes vs object property

Tests:

Array.includes
const arr = ['a', 'b', 'c', 'd', 'e', 'f', 'g'] const hasA = arr.includes('a') const hasG = arr.includes('g') const hasD = arr.includes('d')
Object property
const obj = { ['a']: true, ['b']: true, ['c']: true, ['d']: true, ['e']: true, ['f']: true, ['g']: true } const hasA = obj['a'] const hasG = obj['g'] const hasD = obj['d']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes
Object property

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36

Browser/OS: Chrome 113 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.includes	1032481536.0 Ops/sec
Object property	96342016.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

The provided JSON represents two test cases: `Array.includes` and `Object property`. Both tests compare the performance of checking if an element exists in an array using the `includes()` method versus accessing the property directly on an object.

**Options compared:**

1. **`arr.includes('a')`**: This option checks if the string `'a'` is present in the array `const arr = ['a', 'b', 'c', 'd', 'e', 'f', 'g']`.
2. **`obj['a']`**: This option accesses the property `'a'` directly on the object `const obj = { ['a']: true, ['b']: true, ['c']: true, ['d']: true, ['e']: true, ['f']: true, ['g']: true }`.

**Pros and cons of each approach:**

1. **`arr.includes('a')`**:
	* Pros:
		+ More concise and readable code.
		+ Easy to add or remove elements from the array without modifying the code.
	* Cons:
		+ May be slower due to the additional overhead of searching for the element in the array.
2. **`obj['a']`**:
	* Pros:
		+ Often faster, as it directly accesses a property on an object.
	* Cons:
		+ Less readable and more prone to errors if the property name is incorrect or changes.
		+ More verbose code.

The choice between these two approaches depends on the specific use case and personal preference. If readability and simplicity are more important than performance, `arr.includes('a')` might be a better choice. However, if speed is critical, accessing properties directly (`obj['a']`) might be a better option.

**Library usage:**

Neither of the test cases uses any libraries beyond the built-in JavaScript functionality.

**Special JS feature or syntax:**

There are no special JavaScript features or syntaxes being used in these test cases. They are straightforward examples that demonstrate the performance difference between two common use cases in JavaScript.

**Other alternatives:**

To test similar scenarios, other approaches could be:

1. **Using `Array.indexOf()` instead of `includes()```**: This would check if an element is present at a specific index in the array.
2. **Checking if an object has a property using `in` operator**: Instead of accessing properties directly (`obj['a']`), you could use the `in` operator to check if an object has a certain property.

For example:

```javascript
const obj = { foo: 'bar' };
if ('foo' in obj) {
  console.log('Object has a property');
}
```

Keep in mind that these alternatives might not provide exactly the same performance characteristics as `includes()` or accessing properties directly.

Related benchmarks:

Array.includes vs object property (version: 0)

Comparing performance of: Array.includes vs Object property

Created: one year ago by: Guest

Jump to the latest result

Array.includes

Object property

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):