Benchmark: Array.includes vs Set.has v3

Script Preparation code:

var testArr = [];
for(let i = 0; i < 100000; i++) {
  testArr.push(i);
}
var testSet = new Set(testArr);
var valuesToCheck = [0, 10, 200, 3000, 40000 ,500000];

Tests:

Array.includes
let summ = 0; valuesToCheck.forEach(v => { if (testArr.includes(v)) { summ += v; } }); return summ;
Set.has
let summ = 0; valuesToCheck.forEach(v => { if (testSet.has(v)) { summ += v; } }); return summ;

Historical Performance Data aggregated from 27 community runs

Desktop Results:

Chrome 19 runs

Set.has

23.3M/s

Array.includes

82K/s

Fastest: Set.has (283.6x faster)

View exact numbers

✓ Set.has: 23,266,376 ops/sec
• Array.includes: 82,053 ops/sec

Firefox 8 runs

Set.has

17.6M/s

Array.includes

12K/s

Fastest: Set.has (1475.3x faster)

View exact numbers

✓ Set.has: 17,598,264 ops/sec
• Array.includes: 11,929 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.includes
Set.has

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 17 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36

Browser/OS: Chrome 151 on Windows

View result in a separate tab

Set.has

19.9M/s

Array.includes

45K/s

View exact numbers

Test name	Executions per second
✓ Set.has	19,872,814 Ops/sec
Array.includes	45,217 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 benchmark and explain what's being tested, the options compared, pros and cons of each approach, and other considerations.

**Benchmark Definition**

The benchmark definition is a JSON object that describes two test cases:

1. "Array.includes"
2. "Set.has v3"

The script preparation code generates an array `testArr` with 100,000 elements and creates a set `testSet` from this array. The `valuesToCheck` array contains five values to check for membership.

**Options Compared**

Two options are compared:

1. **Array.includes**: This method checks if a value exists in the array.
2. **Set.has**: This method checks if a value exists in the set.

**Approaches and Considerations**

Both approaches have pros and cons:

**Array.includes:**

Pros:

* Widely supported by most browsers
* Simple to implement

Cons:

* Can be slower for large arrays due to the need to scan through elements
* Can lead to unnecessary iterations if the value is not found in the array

**Set.has:**

Pros:

* Faster lookup times compared to Array.includes, especially for large sets
* More efficient use of memory since sets automatically eliminate duplicates

Cons:

* Not all browsers support the Set API (e.g., older versions of Chrome)
* Requires additional code to create and manage the set

In general, Set.has is a better approach when dealing with large datasets or performance-critical applications. However, Array.includes may be preferred in situations where simplicity and minimal code changes are more important.

**Library/Function:**

The Set API is used in the "Set.has" test case. The Set API is a built-in JavaScript object that allows you to store unique values, eliminating duplicates. It's implemented as an iterator, which makes it efficient for lookup operations.

**Special JS Feature/Syntax:**

There are no special JavaScript features or syntaxes being tested in this benchmark. Both Array.includes and Set.has use standard JavaScript methods.

**Alternatives:**

If you need to compare the performance of other membership tests, such as:

* `Array.indexOf()`: This method returns the index of a value within an array. If the value is not found, it returns -1.
* `Object.contains()`: This method is part of the ECMAScript 2015 (ES6) standard and checks if a property exists in an object.
* `Map.has()`: Similar to Set.has, but for Map objects.

Keep in mind that these alternatives may have different performance characteristics or be supported by only certain browsers.

Array.includes vs Set.has v3 (version: 0) Benchmark.js

Comparing performance of: `Array.includes vs Set.has`

Created: 5 years ago by: Guest

Go to the latest result

Array.includes

Set.has

Historical Performance Data aggregated from 27 community runs

Desktop Results:

Chrome 19 runs

Firefox 8 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Array.includes vs Set.has v3 (version: 0) Benchmark.js

Comparing performance of: Array.includes vs Set.has

Created: 5 years ago by: Guest

Go to the latest result

Array.includes

Set.has

Historical Performance Data aggregated from 27 community runs

Desktop Results:

Chrome 19 runs

Firefox 8 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Array.includes vs Set.has`