Benchmark: iso date string sort comparison

Script Preparation code:

var dates = [
  '2021-11-22T11:00:00.000Z',
  '2021-11-22T07:00:00.000Z',
  '2021-11-24T12:30:00.000Z',
  '2021-11-24T07:00:00.000Z',
  '2021-11-24T07:00:00.000Z',
  '2021-11-26T07:00:00.000Z',
  '2021-11-26T12:30:00.000Z',
  '2021-11-26T12:30:00.000Z',
  '2021-11-27T11:00:00.000Z',
  '2021-11-27T12:30:00.000Z',
  '2021-09-22T11:00:00.000Z',
  '2021-09-22T07:00:00.000Z',
  '2021-09-24T12:30:00.000Z',
  '2021-09-24T07:00:00.000Z',
  '2021-09-24T07:00:00.000Z',
  '2021-09-26T07:00:00.000Z',
  '2021-05-26T12:30:00.000Z',
  '2021-12-26T12:30:00.000Z',
  '2021-09-27T11:00:00.000Z',
  '2021-09-27T12:30:00.000Z',
];

Tests:

sort
const sorted = dates.sort();
localcompare
const sorted = dates.sort((a,b)=>a.localeCompare(b));
manual compare
const sorted = dates.sort(( a, b )=> a < b ? -1 : a > b ? 1 : 0);
date convert to date + sort a-b (timezone safe)
const sorted = dates.map(date=>new Date(date)).sort(( a, b )=> a-b);
date convert to timestamp + sort (timezone safe)
const sorted = dates.map(date=>Date.parse(date)).sort();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
sort
localcompare
manual compare
date convert to date + sort a-b (timezone safe)
date convert to timestamp + sort (timezone safe)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 27 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
sort	4218137.0 Ops/sec
localcompare	1938421.8 Ops/sec
manual compare	2549318.8 Ops/sec
date convert to date + sort a-b (timezone safe)	230108.9 Ops/sec
date convert to timestamp + sort (timezone safe)	389353.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its various test cases.

**Benchmark Definition**

The benchmark is designed to compare different approaches for sorting a list of ISO dates in JavaScript. The input data is stored in an array `dates` containing 20 unique ISO date strings, including both valid and invalid timestamps.

**Options being compared**

There are four main options being tested:

1. **Native sort**: Using the built-in `sort()` method without any custom comparison function.
2. **localeCompare**: Utilizing the `localeCompare()` method to compare dates, which is a part of the JavaScript Standard Library.
3. **Manual comparison**: Implementing a custom comparison function using the `<` and `>` operators to sort the dates.
4. **Date conversion and sorting**: Converting each date string to a Date object using `Date.parse()` or `new Date()`, and then sorting them.

**Pros and cons of each approach**

1. **Native sort**: This method is fast and efficient, but it may not work correctly for all edge cases, such as invalid dates or dates in different time zones.
2. **localeCompare**: This method is more robust than native sort, as it takes into account the locale's date formatting rules. However, it can be slower due to its additional processing steps.
3. **Manual comparison**: This approach provides fine-grained control over the sorting process but requires more code and may lead to errors if not implemented correctly.
4. **Date conversion and sorting**: Converting each date string to a Date object ensures that the sorting is done in a timezone-safe manner, but it can be slower than native sort or localeCompare.

**Library usage**

The `localeCompare()` method uses the Internationalization API (I18N) to perform the comparison, which is a built-in part of modern JavaScript engines. The `Date` constructor and `Date.parse()` method are also part of the JavaScript Standard Library.

**Special JS features or syntax**

No special features or syntax are explicitly mentioned in this benchmark.

**Alternatives**

There are several alternative approaches for sorting dates in JavaScript, including:

1. Using a library like moment.js or Luxon, which provide more robust date parsing and formatting capabilities.
2. Implementing custom date parsing using regular expressions or string manipulation techniques.
3. Utilizing a different data structure, such as a binary search tree, to sort the dates.

Note that these alternatives may offer improved performance or flexibility but come with their own trade-offs in terms of code complexity or added dependencies.

Related benchmarks:

iso date string sort comparison (version: 0)

compares ways of sorting a list of dates in the form of ISO dates

Comparing performance of: sort vs localcompare vs manual compare vs date convert to date + sort a-b (timezone safe) vs date convert to timestamp + sort (timezone safe)

Created: 3 years ago by: Guest

Jump to the latest result

sort

localcompare

manual compare

date convert to date + sort a-b (timezone safe)

date convert to timestamp + sort (timezone safe)

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):