Benchmark: Memoized Intl.NumberFormat vs fresh instances

Script Preparation code:

window.cache = new Map();

window.format = (locale, currency, value) => new Intl.NumberFormat(locale, { style: 'currency', currency }).format(value);

window.memoizedFormat = (locale, currency, value) => {
  const key = [locale, currency];
  let formatter = window.cache.get(key);
  
  if (!formatter) {
    formatter = new Intl.NumberFormat(locale, { style: 'currency', currency });
    window.cache.set(key, formatter);
  }
  
  return formatter.format(value);
};

Tests:

new Intl.NumberFormat
window.format('pt-BR', 'BRL', 100_346_999.21);
memoized instance
window.memoizedFormat('pt-BR', 'BRL', 100_346_999.21);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Intl.NumberFormat
memoized instance

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36

Browser/OS: Chrome 140 on Windows

View result in a separate tab

Test name	Executions per second
new Intl.NumberFormat	42824.3 Ops/sec
memoized instance	43924.4 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 its test cases.

**Benchmark Overview**

The benchmark compares two approaches to formatting numbers in JavaScript: using a fresh instance of `Intl.NumberFormat` versus creating a memoized instance. The goal is to determine which approach provides better performance.

**Options Compared**

Two options are compared:

1. **Fresh Instance**: Using a new instance of `Intl.NumberFormat` every time it's needed.
2. **Memoized Instance**: Creating a single, cached instance of `Intl.NumberFormat` and reusing it for subsequent requests with the same locale and currency settings.

**Pros and Cons**

* **Fresh Instance**:
	+ Pros: Easy to implement, no cache management required.
	+ Cons: Creates a new instance every time, which can lead to performance issues due to the overhead of creating and destroying objects.
* **Memoized Instance**:
	+ Pros: Reuses the cached instance, reducing overhead and improving performance.
	+ Cons: Requires additional memory for caching, and cache invalidation may be necessary when locale or currency settings change.

**Library and Purpose**

`Intl.NumberFormat` is a built-in JavaScript library that formats numbers according to the user's locale. It provides a standardized way of formatting numbers in various ways, such as currency, decimal separator, and group separator.

**Special JS Feature/Syntax**

None mentioned explicitly in this benchmark. However, it's worth noting that `Intl.NumberFormat` uses Unicode code points for its formatting options, which allows for support of various languages and locales.

**Other Alternatives**

If you're looking for alternatives to memoizing instances of `Intl.NumberFormat`, consider the following:

* **LruCache**: A popular caching library for JavaScript that can be used with `Intl.NumberFormat` instances.
* **WeakMap**: A built-in JavaScript data structure that can be used as a cache, allowing you to store and retrieve cached instances of `Intl.NumberFormat`.
* **Custom caching solution**: Implementing your own caching mechanism using JavaScript objects or other libraries.

In summary, the benchmark compares two approaches to formatting numbers in JavaScript: creating fresh instances versus memoizing instances. The memoized approach shows better performance due to reduced overhead, but requires additional memory for caching and cache invalidation.

Related benchmarks:

Memoized Intl.NumberFormat vs fresh instances (version: 0)

Comparing performance of: new Intl.NumberFormat vs memoized instance

Created: 2 years ago by: Guest

Jump to the latest result

new Intl.NumberFormat

memoized instance

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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