Benchmark: Iterate-Set - MeasureThat.net

Script Preparation code:

var fewItemSet = new Set([1, 2, 3]);
var manyItemSet = new Set(Array.from({ length: 1000 }, (_, i) => i));

Tests:

for of: few items
let result = 0; for (const item of fewItemSet) { result += item; }
for of: many items
let result = 0; for (const item of manyItemSet) { result += item; }
convert to array: few items
let result = 0; const arr = Array.from(fewItemSet); for (let i = arr.length; i--;) { result += arr[i]; }
convert to array: many items
let result = 0; const arr = Array.from(manyItemSet); for (let i = arr.length; i--;) { result += arr[i]; }
native iterator: few items
let result = 0; let val = null; const iter = fewItemSet.values(); while (!(val = iter.next()).done) { result += val.value; }
native iterator: many items
let result = 0; let val = null; const iter = manyItemSet.values(); while (!(val = iter.next()).done) { result += val.value; }
native iterator w/ size: few items
let result = 0; let iter = fewItemSet.values(); for (let i = fewItemSet.size; i--;) { result += iter.next().value; }
native iterator w/ size: many items:
let result = 0; let iter = manyItemSet.values(); for (let i = manyItemSet.size; i--;) { result += iter.next().value; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for of: few items
for of: many items
convert to array: few items
convert to array: many items
native iterator: few items
native iterator: many items
native iterator w/ size: few items
native iterator w/ size: many items:

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 25 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:136.0) Gecko/20100101 Firefox/136.0

Browser/OS: Firefox 136 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
for of: few items	17533944.0 Ops/sec
for of: many items	119845.6 Ops/sec
convert to array: few items	16692315.0 Ops/sec
convert to array: many items	166692.4 Ops/sec
native iterator: few items	17871768.0 Ops/sec
native iterator: many items	110232.7 Ops/sec
native iterator w/ size: few items	19069188.0 Ops/sec
native iterator w/ size: many items:	110720.4 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Definition**

The provided JSON represents a benchmark definition for a JavaScript microbenchmark. The `Script Preparation Code` section defines two sets, `fewItemSet` and `manyItemSet`, which are used to test different scenarios.

Here's a brief explanation of what's being tested:

*   `Iterate-Set`: This benchmark tests the performance of iterating over a set using three different approaches:
    *   `for...of` loop
    *   Converting the set to an array and iterating over it with a traditional `for` loop
    *   Using a native iterator (`values()`) to iterate over the set

**Options Compared**

The benchmark compares the performance of these three approaches:

*   **For-each loop**: This is a modern JavaScript syntax that allows you to iterate over an iterable (like a set) without creating an intermediate array. It's generally faster and more memory-efficient than traditional `for` loops.
*   **Converting to Array**: In this approach, the set is converted to an array, which requires additional memory allocation. This method can be slower due to the extra overhead of creating an array.

**Pros and Cons**

Here are some pros and cons for each approach:

*   **For-each loop**:
    *   Pros: Faster execution time, less memory usage, more concise code.
    *   Cons: May not work as expected with certain data structures or older JavaScript versions.
*   **Converting to Array**:
    *   Pros: Can be used in older JavaScript versions or with specific data structures that don't support `for...of`.
    *   Cons: Requires additional memory allocation, potentially slower execution time.

**Native Iterator**

The native iterator (`values()`) approach uses a built-in method provided by modern browsers to iterate over sets. This method is generally faster and more efficient than the other two approaches.

*   Pros:
    *   Fastest execution time
    *   Minimal memory usage
    *   Concise code
*   Cons: May not work in older JavaScript versions or with specific data structures.

**Convert to Array**

Converting a set to an array and iterating over it is a common approach, but it may incur additional overhead due to the extra memory allocation required for the array.

**For-each Loop vs. Native Iterator**

In this benchmark, the `for...of` loop and native iterator (`values()`) approaches are generally faster than the converting-to-array approach. This suggests that modern browsers optimize these methods for better performance.

**Conclusion**

The JavaScript microbenchmark demonstrates the importance of choosing the right iteration method depending on the specific use case, data structure, and browser version. While `for...of` loops offer a concise and efficient way to iterate over sets, native iterators can provide even faster execution times in modern browsers.

Related benchmarks:

Iterate-Set (version: 3)

Iterate over a set.

Comparing performance of: for of: few items vs for of: many items vs convert to array: few items vs convert to array: many items vs native iterator: few items vs native iterator: many items vs native iterator w/ size: few items vs native iterator w/ size: many items:

Created: 4 years ago by: Registered User

Jump to the latest result

for of: few items

for of: many items

convert to array: few items

convert to array: many items

native iterator: few items

native iterator: many items

native iterator w/ size: few items

native iterator w/ size: many items:

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):