Benchmark: New set vs set clear

Script Preparation code:

const permSet = new Set()
for (let i = 0; i < 100; i++) {
  permSet.add(Math.floor(Math.random() * 100000));
}

Tests:

new set
permSet = new Set()
clear set
permSet.clear()

Historical Performance Data aggregated from 53 community runs

Desktop Results:

Chrome 35 runs

clear set

11.0M/s

new set

2.6M/s

Fastest: clear set (4.2x faster)

View exact numbers

✓ clear set: 10,974,160 ops/sec
• new set: 2,617,665 ops/sec

Firefox 18 runs

clear set

83.8M/s

new set

0/s

View exact numbers

✓ clear set: 83,796,768 ops/sec
• new set: 0 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new set
clear set

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser/OS: Firefox 146 on Linux

View result in a separate tab

clear set

105.1M/s

new set

0/s

View exact numbers

Test name	Executions per second
✓ clear set	105,082,456 Ops/sec
new set	0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided JSON and explain what's being tested, compared, and some of the considerations involved.

**Benchmark Definition**

The benchmark definition is testing two approaches: creating a new Set object (`"permSet = new Set()"`) versus clearing an existing Set object (`"permSet.clear()"`).

A Set in JavaScript is a collection of unique values. It's similar to an array, but it doesn't allow duplicate values.

**Options Compared**

The two options being compared are:

1. **Creating a new Set object**: This approach creates a fresh Set instance and populates it with 100 random integers.
2. **Clearing an existing Set object**: This approach clears the existing `permSet` object (which is already populated) and does nothing else.

**Pros and Cons of Each Approach**

1. **Creating a new Set object**:
	* Pros: Creates a fresh, empty Set instance from scratch, which can be faster for certain use cases.
	* Cons: Requires more memory allocation and potentially slower due to the overhead of creating a new object.
2. **Clearing an existing Set object**:
	* Pros: Reuses an already created and populated Set instance, reducing memory allocation and potential overhead.
	* Cons: Can be slower if the set needs to be rebuilt or reserialized, as it involves clearing the existing data.

**Other Considerations**

* Memory allocation and deallocation can impact performance, especially for large datasets.
* The `clear()` method is generally faster than creating a new object from scratch because it only requires updating the internal data structure of the Set instance.

**Library and Purpose**

In this benchmark, no specific library is used. However, if you were to create a real-world application using JavaScript, libraries like Lodash or Ramda might be useful for working with Sets, but they are not relevant to this specific benchmark.

**Special JS Feature or Syntax**

There's no special JS feature or syntax being tested in this benchmark. The focus is on the performance comparison between creating a new Set object and clearing an existing one.

**Alternatives**

If you were to write your own JavaScript microbenchmark, here are some alternatives:

* Create a simple array-based benchmark: Replace Sets with arrays and test how quickly they can be populated or cleared.
* Use a library like WebPerf or Microbench to create and run benchmarks.
* Implement the benchmark yourself using a framework like Jest or Mocha.

Keep in mind that these alternatives might not provide the same level of nuance and detail as MeasureThat.net, but they can still help you understand performance characteristics in JavaScript.

New set vs set clear (version: 0)

Comparing performance of: `new set vs clear set`

Created: 5 years ago by: Guest

Go to the latest result

new set

clear set

Historical Performance Data aggregated from 53 community runs

Desktop Results:

Chrome 35 runs

Firefox 18 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

New set vs set clear (version: 0)

Comparing performance of: new set vs clear set

Created: 5 years ago by: Guest

Go to the latest result

new set

clear set

Historical Performance Data aggregated from 53 community runs

Desktop Results:

Chrome 35 runs

Firefox 18 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Comparing performance of: `new set vs clear set`