Benchmark: Set has vs object key 3

Script Preparation code:

var obj = (new Array(1000)).fill(null).reduce((prev, newVal) => {prev[Math.random() + ''] = Math.random() + ''; return prev; }, { sausage: 'tst' });
var array = Object.keys(obj);
var set = new Set(array);

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Includes
Object[key]
Set.has

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, the options compared, pros and cons of each approach, library usage, special JavaScript features or syntax (if any), and alternative approaches.

**Benchmark Definition**

The benchmark consists of three test cases:

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

Each test case is a microbenchmark that measures the performance of a specific JavaScript operation.

**Script Preparation Code**

The script preparation code generates an object with 1000 properties, where each property has a random key and value. The keys are stored in an array using `Object.keys(obj)`.

```javascript
var obj = (new Array(1000)).fill(null).reduce((prev, newVal) => {prev[Math.random() + ''] = Math.random() + ''; return prev; }, { sausage: 'tst' });
```

This code creates a large object with random keys and values. The `sausage` property is specifically created to test the three different operations.

**Options Compared**

The benchmark compares the performance of three different ways to find if an array contains a value:

1. **Array includes**: Using the `includes()` method to check if a value exists in an array.
2. **Object key access**: Using the bracket notation (`obj['sausage']`) to access and retrieve a property from an object by its key.
3. **Set has**: Using the `has()` method of a Set data structure to check if a value exists.

**Pros and Cons**

Here's a brief overview of each approach:

1. **Array includes**:
	* Pros: Simple, widely supported, and efficient for large arrays.
	* Cons: Can be slower than other methods for small arrays or when the element is not present in the array.
2. **Object key access**:
	* Pros: Fast and efficient for objects with a fixed number of properties.
	* Cons: Slower for large objects or when the property is not found, as it involves object lookup and property access.
3. **Set has**:
	* Pros: Fast and efficient for large sets or when checking for membership in a set.
	* Cons: Requires a Set data structure, which may add overhead for small datasets.

**Library Usage**

The benchmark uses the `Set` data structure from the JavaScript built-in API. There are no external libraries used in this benchmark.

**Special JavaScript Features/Syntax (None)**

There are no special JavaScript features or syntax used in this benchmark beyond standard language constructs.

**Alternative Approaches**

Some alternative approaches for similar microbenchmarks might include:

1. **Using a sparse array**: Instead of creating an object with random keys, you could create a sparse array using `Array(1000).fill(null)` and then populate it with values.
2. **Using a Map data structure**: A Map can provide faster lookups compared to objects or Sets, especially for large datasets.

Keep in mind that the choice of approach depends on the specific requirements and characteristics of your benchmark, as well as the intended use case for the results.

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36 Edg/126.0.0.0

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
Includes	16963538.0 Ops/sec
Object[key]	16097709.0 Ops/sec
Set.has	15704961.0 Ops/sec

Related benchmarks:

Set has vs object key 3 (version: 0)

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

Comparing performance of: Includes vs Object[key] vs Set.has

Created: 5 months ago by: Guest

Jump to the latest result

Includes

Object[key]

Set.has

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):