Benchmark: Intl.DateTimeFormat new vs cached with lookup

Script Preparation code:

const TWO_DIGIT = '2-digit';

var options = {
      month: TWO_DIGIT,
      year: 'numeric',
      day: TWO_DIGIT,
      hour: TWO_DIGIT,
      hour12: false,
      minute: TWO_DIGIT,
      second: TWO_DIGIT,
    }

var cache = {
  [JSON.stringify(options)]: new Intl.DateTimeFormat('en-US', options)
};

var date = new Date();
var number = date.getTime();

Tests:

new Intl.DateTimeFormat.format(date)
new Intl.DateTimeFormat('en-US', options).format(date);
cached Intl.DateTimeFormat.format(date)
cache[JSON.stringify(options)].format(date);
new Intl.DateTimeFormat.format(number)
new Intl.DateTimeFormat('en-US', options).format(number);
cached Intl.DateTimeFormat.format(number)
cache[JSON.stringify(options)].format(number);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Intl.DateTimeFormat.format(date)
cached Intl.DateTimeFormat.format(date)
new Intl.DateTimeFormat.format(number)
cached Intl.DateTimeFormat.format(number)

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/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
new Intl.DateTimeFormat.format(date)	8817.6 Ops/sec
cached Intl.DateTimeFormat.format(date)	231447.5 Ops/sec
new Intl.DateTimeFormat.format(number)	8952.5 Ops/sec
cached Intl.DateTimeFormat.format(number)	245263.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested, compared, and analyzed.

**Benchmark Purpose:**

The primary goal of this benchmark is to compare the performance impact of caching calls to `new Intl.DateTimeFormat` in JavaScript. Specifically, it tests the difference between creating a new instance of `Intl.DateTimeFormat` each time and reusing an existing cached instance.

**Options being compared:**

There are two main options being compared:

1. **New Instance**: Creating a new instance of `Intl.DateTimeFormat` using `new Intl.DateTimeFormat('en-US', options).format(date)` or `new Intl.DateTimeFormat('en-US', options).format(number)`. This approach creates a new instance each time the function is called, which can lead to slower performance.
2. **Cached Instance**: Reusing an existing cached instance of `Intl.DateTimeFormat` using `cache[JSON.stringify(options)].format(date)` or `cache[JSON.stringify(options)].format(number)`. This approach caches the instance creation and reuses it each time.

**Pros and Cons:**

1. **New Instance**
	* Pros:
		+ Easier to implement and understand, as it doesn't require caching.
		+ Can be beneficial for development environments or debugging purposes, where a new instance is needed frequently.
	* Cons:
		+ Slower performance due to repeated instance creation.
2. **Cached Instance**
	* Pros:
		+ Provides faster performance by reusing the cached instance.
		+ Can improve overall application responsiveness and user experience.

**Library:**

The benchmark uses the `Intl.DateTimeFormat` API, which is a part of the modern JavaScript Standard Library. This library provides a standardized way to format dates and numbers in different locales.

**Special JS Feature or Syntax:**

This benchmark does not use any special JavaScript features or syntax beyond what's standard for modern browsers. However, it does rely on the `JSON.stringify()` function to cache the instance options, which is a built-in feature of JavaScript.

**Other Alternatives:**

If you want to explore alternative approaches, here are some considerations:

1. **Use a caching library**: There are several caching libraries available for JavaScript, such as LRU Cache or Memcached, that can be used to implement caching in your application.
2. **Optimize instance creation**: Depending on the specific requirements of your application, you might be able to optimize instance creation by reducing the number of options passed to `Intl.DateTimeFormat` or using a more efficient caching strategy.

Keep in mind that this benchmark is specifically designed to compare the performance impact of caching calls to `new Intl.DateTimeFormat`. If you have different use cases or requirements, you may need to modify the benchmark or explore alternative approaches.

Related benchmarks:

Intl.DateTimeFormat new vs cached with lookup (version: 0)

measure the perf impact of caching calls to new Intl.DateTimeFormat

Comparing performance of: new Intl.DateTimeFormat.format(date) vs cached Intl.DateTimeFormat.format(date) vs new Intl.DateTimeFormat.format(number) vs cached Intl.DateTimeFormat.format(number)

Created: one year ago by: Guest

Jump to the latest result

new Intl.DateTimeFormat.format(date)

cached Intl.DateTimeFormat.format(date)

new Intl.DateTimeFormat.format(number)

cached Intl.DateTimeFormat.format(number)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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