Benchmark: set vs array iteration

Script Preparation code:

var a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var b = new Set(a)

Tests:

array
for (const x of a) {}
set
for (const x of b) {}

Historical Performance Data aggregated from 155 community runs

Desktop Results:

Chrome 113 runs

array

29.9M/s

set

21.0M/s

Fastest: array (1.4x faster)

View exact numbers

✓ array: 29,921,774 ops/sec
• set: 21,028,242 ops/sec

Firefox 23 runs

array

15.1M/s

set

5.8M/s

Fastest: array (2.6x faster)

View exact numbers

✓ array: 15,116,546 ops/sec
• set: 5,755,930 ops/sec

Mobile Results:

Chrome 12 runs

array

64.9M/s

set

33.8M/s

Fastest: array (1.9x faster)

View exact numbers

✓ array: 64,924,656 ops/sec
• set: 33,782,480 ops/sec

Safari 7 runs

array

62.9M/s

set

28.3M/s

Fastest: array (2.2x faster)

View exact numbers

✓ array: 62,930,528 ops/sec
• set: 28,291,592 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
array
set

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Browser/OS: Chrome 146 on Mac OS X 10.15.7

View result in a separate tab

array

162.5M/s

set

87.4M/s

View exact numbers

Test name	Executions per second
✓ array	162,496,544 Ops/sec
set	87,447,760 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Purpose**
The benchmark measures the performance difference between iterating over an array and iterating over a Set (a data structure that automatically removes duplicates) using a `for...of` loop.

**Comparison Options**

1. **Array Iteration**: The first option uses a traditional array (`var a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]`) and iterates over its elements using a `for...of` loop.
2. **Set Iteration**: The second option uses a Set created from the array (`var b = new Set(a)`) and iterates over its elements using another `for...of` loop.

**Pros and Cons of Each Approach**

* **Array Iteration**:
	+ Pros: More straightforward, efficient for small to medium-sized datasets.
	+ Cons: Can be slower for large datasets due to the overhead of searching for duplicate values in the Set.
* **Set Iteration**:
	+ Pros: Efficiently removes duplicates, potentially faster for large datasets since it doesn't require searching for duplicates.
	+ Cons: Requires more memory to store the Set, and iterating over a Set can be slower than iterating directly over an array.

**Library Used (if applicable)**
In this benchmark, no specific library is used besides JavaScript's built-in `Set` object. However, in general, when working with large datasets or performance-critical code, libraries like `lodash` or `fast-sets` might be used to optimize iteration and data processing operations.

**Special JS Features/Syntax (if applicable)**
The benchmark uses the `for...of` loop syntax, which is a modern JavaScript feature introduced in ECMAScript 2015. This allows for concise iteration over arrays, Sets, or other iterable objects without the need for traditional indexing.

**Other Alternatives**

For alternative approaches to iterating over arrays and Sets, consider:

* Using `Array.prototype.forEach()` or `Set.prototype.forEach()` instead of `for...of` loops.
* Utilizing libraries like `lodash` for optimized array and Set operations.
* Exploring other data structures, such as `Map` or `WeakSet`, which offer different iteration patterns.

Keep in mind that the choice of iteration approach depends on the specific requirements of your project, including performance considerations, memory usage, and code readability.

set vs array iteration (version: 0)

Comparing performance of: `array vs set`

Created: 4 years ago by: Guest

Go to the latest result

array

set

Historical Performance Data aggregated from 155 community runs

Desktop Results:

Chrome 113 runs

Firefox 23 runs

Mobile Results:

Chrome 12 runs

Safari 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

set vs array iteration (version: 0)

Comparing performance of: array vs set

Created: 4 years ago by: Guest

Go to the latest result

array

set

Historical Performance Data aggregated from 155 community runs

Desktop Results:

Chrome 113 runs

Firefox 23 runs

Mobile Results:

Chrome 12 runs

Safari 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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Comparing performance of: `array vs set`