Benchmark: index vs map111 - MeasureThat.net

Script Preparation code:

var myArray = ['a', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1', 1, 'a', 2, '1'];

Tests:

1
var unique = myArray.filter((value, index, array) => array.indexOf(value) === index);
2
let map = {}; myArray.forEach(v => { map[v]=true }) Object.keys(map);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1
2

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser/OS: Chrome 129 on Windows

View result in a separate tab

Test name	Executions per second
1	1230217.9 Ops/sec
2	866283.4 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 provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is defined by two individual test cases:

1. `index vs map111`: This test case compares the performance of two approaches to achieve a similar result:
	* **Approach 1: Using `Array.prototype.indexOf()` and `filter()`**: This approach uses the `indexOf()` method to find the index of each element in the array, and then filters out elements that don't have an index equal to their value.
	* **Approach 2: Using a `map` object**: This approach creates a `map` object and iterates over the array using `forEach()`, adding each value as a key in the map. Finally, it calls `Object.keys()` on the map to retrieve its keys (which are equivalent to indices).
2. The other test case is not relevant for this explanation.

**What's being tested**

The benchmark tests the performance of two approaches to iterate over an array and find indices:

* **Approach 1: Using `Array.prototype.indexOf()` and `filter()`:** This approach uses a more traditional way to achieve iteration, but it has some limitations:
	+ It requires the presence of each element in the array's index map.
	+ It may perform slower for large arrays due to the overhead of the `indexOf()` method.

* **Approach 2: Using a `map` object**: This approach uses a more modern way to achieve iteration, which is often faster and more efficient:
	+ It allows for easy key-value access using `Object.keys()`.
	+ However, it may have performance implications due to the overhead of creating a new map object.

**Pros and Cons**

Here's a summary of the pros and cons of each approach:

* **Approach 1: Using `Array.prototype.indexOf()` and `filter()`**:
	+ Pros: Easy to understand and implement.
	+ Cons: May perform slower for large arrays, requires element presence in index map.
* **Approach 2: Using a `map` object**:
	+ Pros: Often faster, easier key-value access using `Object.keys()`.
	+ Cons: Requires more memory (for the map object), may have performance implications due to map creation overhead.

**Libraries and special features**

There are no libraries explicitly mentioned in the benchmark definition. However, the use of `Array.prototype.indexOf()` and `filter()` is a native JavaScript feature that's widely supported.

The use of `map` objects is also a native JavaScript feature, but it might not be as commonly used for iteration purposes.

**Other alternatives**

If you're looking for alternative ways to iterate over an array in JavaScript, here are some options:

* **Using a `for...of` loop**: This is another modern way to iterate over arrays, which can be faster and more efficient than the approaches tested in this benchmark.
* **Using a `reduce()` method**: This can also be used for iteration, although it might not be as suitable for all use cases.

Overall, the choice of approach depends on the specific requirements of your project, including performance considerations, memory usage, and code readability.

Related benchmarks:

index vs map111 (version: 0)

Comparing performance of: 1 vs 2

Created: one year ago by: Guest

Jump to the latest result

1

2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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