Benchmark: array includes vs set has (x-small list)

Script Preparation code:

var array = [
    'auto',
    'no-flex',
];

var ArrayProtoIncludes = Array.prototype.includes;
var ReflectApply = Reflect.apply;

var aSet = new Set(array);

Tests:

Array.includes
var b = array.includes('no-flex') var c = array.includes('boop')
Set.has
var b = aSet.has('no-flex') var c = aSet.has('boop')
ArrayProtoIncludes
var b = ReflectApply(ArrayProtoIncludes, array, ['no-flex']); var c = ReflectApply(ArrayProtoIncludes, array, ['boop']);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes
Set.has
ArrayProtoIncludes

Fastest: N/A

Slowest: N/A

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/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.includes	15698956.0 Ops/sec
Set.has	15571068.0 Ops/sec
ArrayProtoIncludes	5073749.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**What is being tested?**

The test cases measure the performance of three different approaches to check if an element exists in an array or set:

1. `Array.prototype.includes()`: This method checks if a specified value (in this case, 'no-flex') exists in the array.
2. `Set.has()` method: This method is used to determine whether an element ('no-flex') exists within a set created from the same array as above.
3. `Reflect.apply(ArrayProtoIncludes, array, ['no-flex'])`: This approach uses the `Reflect.apply()` function to call the `includes()` method on the `ArrayProto` prototype (i.e., the built-in `Array.prototype` object), passing in the array and a string argument ('no-flex').

**Options compared:**

* The three test cases compare the performance of each of these three approaches.
* Another alternative is using the traditional `indexOf()` method for arrays, which is not included in this benchmark. However, since `includes()` has largely replaced `indexOf()` in modern browsers and JavaScript engines, it's worth noting that the results would likely be similar.

**Pros and Cons:**

1. **Array.prototype.includes()**:
	* Pros: Wide browser support (including older versions), easy to use, and efficient for small arrays.
	* Cons: Can be slower than `Set.has()` for very large datasets due to the overhead of searching the array.
2. **Set.has() method**:
	* Pros: Efficient for very large datasets since sets provide O(1) lookup time on average, making it suitable for handling large lists or sets.
	* Cons: Requires a separate set data structure creation and can be slower than `Array.prototype.includes()` for smaller arrays due to the overhead of creating and searching the set.
3. **Reflect.apply(ArrayProtoIncludes, array, ['no-flex'])**:
	* Pros: Provides a more direct access to the built-in `includes()` method without having to create a separate function or prototype chain lookup.
	* Cons: May incur additional overhead due to the use of `Reflect.apply()`, which is not as well optimized as the native `includes()` method.

**Libraries and their purpose:**

* The `Set` library is used to create a set data structure, which is then used in conjunction with the `has()` method. This approach takes advantage of the O(1) lookup time provided by sets for large datasets.
* There is no specific library mentioned in the benchmark definition that is not part of the standard JavaScript specification.

**Special JS features or syntax:**

There are no special features or syntax used beyond what's described above, such as ES6 arrow functions or async/await, which are commonly used in modern JavaScript development.

Related benchmarks:

array includes vs set has (x-small list) (version: 0)

Comparing performance of: Array.includes vs Set.has vs ArrayProtoIncludes

Created: 2 years ago by: Guest

Jump to the latest result

Array.includes

Set.has

ArrayProtoIncludes

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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