Benchmark: Array iter vs set iter

Array iter vs set iter (version: 0)

Iterate over an array vs iterating over a set.

Comparing performance of: for of arr: few items vs for of set: few items vs native loop arr: few items vs native iter set: few items vs for of arr: many items vs for of set: many items vs native loop arr: many items vs native iter set: many items

Created: 5 years ago by: Registered User

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Script Preparation code:

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

Tests:

for of arr: few items
let result = 0; for (const item of fewItemArr) { result += item; }
for of set: few items
let result = 0; for (const item of fewItemSet) { result += item; }
native loop arr: few items
let result = 0; for (let i = fewItemArr.length; i--;) { result += fewItemArr[i]; }
native iter set: few items
let result = 0; let val = null; const iter = fewItemSet.values(); while (!(val = iter.next()).done) { result += val.value; }
for of arr: many items
let result = 0; for (const item of manyItemArr) { result += item; }
for of set: many items
let result = 0; for (const item of manyItemSet) { result += item; }
native loop arr: many items
let result = 0; for (let i = manyItemArr.length; i--;) { result += manyItemArr[i]; }
native iter set: many items
let result = 0; let val = null; const iter = manyItemSet.values(); while (!(val = iter.next()).done) { result += val.value; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for of arr: few items
for of set: few items
native loop arr: few items
native iter set: few items
for of arr: many items
for of set: many items
native loop arr: many items
native iter set: many items

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36

Browser/OS: Chrome 136 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
for of arr: few items	105554000.0 Ops/sec
for of set: few items	78710352.0 Ops/sec
native loop arr: few items	94628632.0 Ops/sec
native iter set: few items	80322080.0 Ops/sec
for of arr: many items	1448271.5 Ops/sec
for of set: many items	618009.0 Ops/sec
native loop arr: many items	426393.5 Ops/sec
native iter set: many items	667540.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the test cases and explain what each one is testing.

**Benchmark Definition**

The benchmark definition provides an overview of the test case. In this case, it's comparing iterating over an array versus iterating over a set.

**Script Preparation Code**

The script preparation code sets up the test environment. It creates two arrays and two sets:

* `fewItemArr` and `fewItemSet`: These are small arrays and sets with only three items.
* `manyItemArr` and `manyItemSet`: These are large arrays and sets with 1000 items.

**Html Preparation Code**

There is no HTML preparation code, which means that the test case is purely JavaScript-related.

**Individual Test Cases**

Each test case measures the performance of a specific iteration method:

1. **for of arr: few items**
	* Iterates over `fewItemArr` using the `for...of` loop.
2. **for of set: few items**
	* Iterates over `fewItemSet` using the `for...of` loop.
3. **native loop arr: few items**
	* Iterates over `fewItemArr` using a native loop (i.e., an explicit `for` loop with indexing).
4. **native iter set: few items**
	* Iterates over `fewItemSet` using the `values()` method of the set.
5. **for of arr: many items**
	* Iterates over `manyItemArr` using the `for...of` loop.
6. **for of set: many items**
	* Iterates over `manyItemSet` using the `for...of` loop.
7. **native loop arr: many items**
	* Iterates over `manyItemArr` using a native loop (i.e., an explicit `for` loop with indexing).
8. **native iter set: many items**
	* Iterates over `manyItemSet` using the `values()` method of the set.

**Library and Framework**

There are no libraries or frameworks explicitly mentioned in the test case. However, it's likely that the JavaScript engine being used is modern enough to support the `for...of` loop and the `values()` method on sets.

**Performance Measurements**

The performance measurements report the number of executions per second for each iteration method. The results suggest that:

* Using a native loop can be faster than using the `for...of` loop, especially for large datasets.
* Iterating over sets using the `values()` method can be slower than iterating over arrays using the `for...of` loop.
* The performance difference between the two iteration methods decreases as the dataset size increases.

Overall, this benchmark suggests that using a native loop and iterating directly on an array or set can be more efficient than using the `for...of` loop or the `values()` method.

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