Benchmark: string.split vs toLocaleString("en-GB")

Script Preparation code:

var dateStr = "2021-08-10T06:00:00.000Z"

Tests:

split
[yyyy,mm,dd,hh,mi] = dateStr.split(/[/:\-T]/) const result =`${dd}/${mm}/${yyyy}, ${hh}:${mi}`
Date toLocaleString
const result = new Date(dateStr).toLocaleString("en-GB")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split
Date toLocaleString

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 11 months 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
split	2319332.0 Ops/sec
Date toLocaleString	1282930.1 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks to compare the performance of different approaches. In this case, we're analyzing a benchmark that tests two ways of formatting dates: using `string.split()` versus using `toLocaleString()`. We'll break down what's tested, compared, pros and cons of each approach, and discuss libraries and special JS features used.

**Benchmark Definition**

The benchmark definition is a JSON object that contains information about the test case:
```json
{
  "Name": "string.split vs toLocaleString(\"en-GB\")",
  "Description": null,
  "Script Preparation Code": "var dateStr = \"2021-08-10T06:00:00.000Z\"",
  "Html Preparation Code": null
}
```
The `Script Preparation Code` specifies a sample date string (`dateStr`) that will be used for the test.

**Test Cases**

There are two individual test cases:
```json
[
  {
    "Benchmark Definition": "[yyyy,mm,dd,hh,mi] = dateStr.split(/[/:\\-T]/)\r\nconst result =`${dd}/${mm}/${yyyy}, ${hh}:${mi}`",
    "Test Name": "split"
  },
  {
    "Benchmark Definition": "const result = new Date(dateStr).toLocaleString(\"en-GB\")",
    "Test Name": "Date toLocaleString"
  }
]
```
Each test case has a `Benchmark Definition` that describes how the date will be formatted and what the resulting code looks like.

**What's being tested**

In each test case, we're testing the performance of two different approaches:

1. **`string.split()`**: The first test case uses `split()` to extract the individual components (year, month, day, hour, minute) from the date string and then concatenates them into a new string using template literals.
2. **`Date.toLocaleString()`**: The second test case uses the `Date` constructor to parse the date string and then calls `toLocaleString()` with a locale (`en-GB`) to format the date.

**Comparison of approaches**

Here's a brief comparison of the two approaches:

* **`string.split()`**:
	+ Pros: Simple, lightweight, and can be easily implemented by hand.
	+ Cons: Error-prone due to the need to handle different date formats and edge cases. Can also lead to performance issues if not optimized correctly.
* **`Date.toLocaleString()`**:
	+ Pros: Efficient, reliable, and widely supported. Provides a standardized way of formatting dates across browsers.
	+ Cons: May have varying output depending on the locale and browser, which can affect performance.

**Library used**

In this benchmark, the `toLocaleString()` method uses the `Date` API, which is a built-in JavaScript library. This means that no external libraries are required to run the test.

**Special JS feature**

There's no special JS feature being used in this benchmark beyond the standard features of the languages (JavaScript).

**Alternative approaches**

Other ways to format dates in JavaScript might include:

* Using regular expressions to extract date components
* Utilizing a third-party library like Moment.js or Luxon for date manipulation and formatting
* Leveraging browser-specific APIs, such as Google's `dateparser` API

Keep in mind that each of these alternatives has its own trade-offs in terms of performance, reliability, and complexity.

I hope this explanation helps!

Related benchmarks:

string.split vs toLocaleString("en-GB") (version: 0)

Comparing performance of: split vs Date toLocaleString

Created: 3 years ago by: Guest

Jump to the latest result

split

Date toLocaleString

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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