Benchmark: Intl.NumberFormat vs toLocalString vs Intl.NumberFormat instantiated

Script Preparation code:

var formatter = Intl.NumberFormat("en-US")

Tests:

Intl.NumberFormat
var a = new Intl.NumberFormat("en-US").format("10000");
toLocalString
var a = "10000".toLocaleString("en-US");
Intl.NumberFormat instantiated
var a = formatter.format("10000")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Intl.NumberFormat
toLocalString
Intl.NumberFormat instantiated

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the provided benchmark data and explain what's being tested.

**Benchmark Overview**

The benchmark compares three approaches to format numbers:

1. `Intl.NumberFormat`: Using the `Intl` API to create a formatted number string with a specific locale (in this case, "en-US").
2. `toLocalString`: Using the `toLocaleString()` method on a numeric value to format it as a localized string.
3. `Intl.NumberFormat instantiated`: Creating an instance of the `Intl.NumberFormat` class and calling its `format()` method with a specific locale (in this case, "en-US").

**Options Compared**

The benchmark compares these three options for formatting numbers:

* **Performance**: Which approach is faster? The benchmark measures the execution time per second for each test.
* **Code Complexity**: How complex is the code required to achieve each format?
* **Locale Support**: How well does each approach handle different locales?

**Pros and Cons of Each Approach**

1. **`Intl.NumberFormat`**:
	* Pros: Well-defined, standardized API, supports multiple locales, and has a clear syntax.
	* Cons: May be slower due to the overhead of creating an instance and accessing its methods.
2. **`toLocalString()`**:
	* Pros: Simple and concise, widely supported in older browsers (prior to ECMAScript 2019), and fast execution time.
	* Cons: Limited locale support, may not produce consistent results across different browsers and systems, and has a more complex syntax than `Intl.NumberFormat`.
3. **`Intl.NumberFormat instantiated`**:
	* Pros: Provides fine-grained control over formatting options, supports multiple locales, and can be faster than `Intl.NumberFormat` due to reduced overhead.
	* Cons: Requires manual locale setup and can lead to code complexity if not used carefully.

**Library Used**

The benchmark uses the `Intl` API, which is a part of the ECMAScript Internationalization API (ECMA-357). The `Intl` API provides a set of standardized interfaces for working with internationalized strings, numbers, dates, and times. In this case, it's used to create an instance of `Intl.NumberFormat` and call its `format()` method.

**Special JS Feature or Syntax**

There are no specific JavaScript features or syntaxes being tested in this benchmark. However, the use of the `Intl` API and locale-specific formatting may require knowledge of internationalization best practices and language-specific formatting conventions (e.g., handling commas vs. periods for decimal separators).

**Other Alternatives**

If you need to format numbers, other alternatives might include:

* Using a library like Moment.js or Luxon, which provide more advanced date and time formatting capabilities.
* Implementing manual formatting using a template engine or string replacement techniques.
* Using a CSS library that includes formatting utilities for strings.

However, the `Intl` API and `toLocalString()` method remain popular choices for simple number formatting due to their simplicity, performance, and widespread browser support.

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/605.1.15 (KHTML, like Gecko) Version/16.4 Safari/605.1.15

Browser/OS: Safari 16 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Intl.NumberFormat	44882.0 Ops/sec
toLocalString	23684994.0 Ops/sec
Intl.NumberFormat instantiated	2930437.8 Ops/sec

Related benchmarks:

Intl.NumberFormat vs toLocalString vs Intl.NumberFormat instantiated (version: 0)

Comparing performance of: Intl.NumberFormat vs toLocalString vs Intl.NumberFormat instantiated

Created: one year ago by: Guest

Jump to the latest result

Intl.NumberFormat

toLocalString

Intl.NumberFormat instantiated

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):