Benchmark: set.has vs. array.includes large 3

Script Preparation code:

var a = [];
for(let i = 0; i < 2000; i++){
  a.push(i);
}
var b = new Set(a)

Tests:

includes
return a.includes(1000)
lookup
return b.has(1000)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
lookup

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark is comparing two approaches to check if an element exists in a set or array: `set.has` (lookup) vs. `array.includes`.

**Script Preparation Code**
```javascript
var a = [];
for (let i = 0; i < 2000; i++) {
  a.push(i);
}
var b = new Set(a);
```
This code creates an array `a` with 2000 elements and a set `b` that contains the same elements as `a`. The script preparation is done before running the actual benchmark, which means it's executed once for both test cases.

**Test Cases**

There are two test cases:

1. **includes**: This test case runs the expression `a.includes(1000)`.
2. **lookup**: This test case runs the expression `b.has(1000)`.

Both expressions will check if the element 1000 exists in either the array or set.

**Options Compared**

The two options being compared are:

* `array.includes()`: A method that checks if an element exists in an array.
* `set.has()`: A method that checks if an element exists in a set.

**Pros and Cons of Each Approach**

* **Array Includes**: Pros:
	+ Wide support across browsers and platforms.
	+ Can be used with arrays of any type, not just integers.
Cons:
	+ May have performance issues for large arrays due to the need to iterate over all elements.
	+ May be slower than set-based lookups for small sets.
* **Set Has**: Pros:
	+ Fast lookup times, especially for large sets (average O(1) time complexity).
	+ More memory-efficient than using an array.
Cons:
	+ Limited support across browsers and platforms (not all browsers support sets).
	+ May not work with arrays of arbitrary types.

**Library/Function Used**

* `Set`: A built-in JavaScript object that represents a collection of unique values. It's used in the script preparation code to create a set `b` containing the elements of array `a`.

**Special JS Feature/Syntax**

None mentioned in this benchmark.

**Other Considerations**

When choosing between `array.includes()` and `set.has()`, consider the following:

* If you need to check for membership in an array or set frequently, using `set.has()` might be a better choice due to its faster lookup times.
* However, if you're working with arrays of arbitrary types or need wide browser support, `array.includes()` might be a more suitable option.

**Alternatives**

Other alternatives to `array.includes()` and `set.has()` include:

* Using `Object.prototype.hasOwnProperty.call(array, value)` for array lookups (less efficient than `includes()`).
* Using `Array.from(set).indexOf(value) + 1` for set lookups (less efficient than `has()`).
* Implementing a custom lookup function using a hash table or similar data structure.

Keep in mind that these alternatives may have different performance characteristics and trade-offs depending on the specific use case.

Related benchmarks:

set.has vs. array.includes large 3 (version: 0)

Comparing performance of: includes vs lookup

Created: 5 years ago by: Guest

Jump to the latest result

includes

lookup

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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