Benchmark: Intl.NumberFormat vs toLocalString vs reuse Intl.NumberFormat

Script Preparation code:

var fmt = new Intl.NumberFormat("en-US");

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Definition**

The benchmark is designed to compare three different approaches for formatting numbers in JavaScript:

1. `Intl.NumberFormat`
2. `toLocaleString`
3. Reusing an already created `Intl.NumberFormat` instance.

**Options Being Compared**

The options being compared are:

* **`Intl.NumberFormat`**: uses the Internationalization API to format numbers according to the specified locale.
* **`toLocaleString`**: uses the built-in `toLocaleString` method to format numbers as a string, with the locale determined by the environment.
* **Reusing an already created `Intl.NumberFormat` instance**: creates a single `Intl.NumberFormat` instance once and reuses it for all iterations of the benchmark.

**Pros and Cons**

Here are some pros and cons of each approach:

* **`Intl.NumberFormat`**:
	+ Pros: provides fine-grained control over formatting options, supports multiple locales.
	+ Cons: requires an extra step to create an instance, may have performance overhead due to frequent creation.
* **`toLocaleString`**:
	+ Pros: simple and easy to use, no additional setup required.
	+ Cons: locale determination can be unpredictable, may not support all formatting options.
* **Reusing `Intl.NumberFormat` instance**:
	+ Pros: reduces the number of instances created, potentially improves performance.
	+ Cons: requires creating a single instance upfront, which may have some overhead.

**Library Used**

In this benchmark, the `Intl.NumberFormat` library is used to format numbers according to the specified locale. The library provides an object-based API for formatting numbers, with various options for controlling the format, such as:

* `locale`: specifies the language and region code for the formatted number.
* `minimumFractionDigits`: controls the minimum number of fractional digits to include in the result.
* `maximumFractionDigits`: controls the maximum number of fractional digits to include in the result.

**Special JS Feature/Syntax**

The benchmark does not use any special JavaScript features or syntax. It is a straightforward test of the formatting capabilities of each approach.

**Alternative Approaches**

Other approaches for formatting numbers in JavaScript could include:

* Using a third-party library, such as Moment.js or Underscore.js.
* Creating a custom function to format numbers based on specific requirements.
* Using a template engine, such as Handlebars or Mustache, to generate formatted strings.

However, these alternatives are not being tested in this benchmark, which focuses specifically on the three approaches mentioned above.

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/16.2 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	22258.4 Ops/sec
toLocalString	12895701.0 Ops/sec
reuse Intl.NumberFormat	1363138.9 Ops/sec

Related benchmarks:

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

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

Created: 3 years ago by: Guest

Jump to the latest result

Intl.NumberFormat

toLocalString

reuse Intl.NumberFormat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):