Benchmark: Intl.NumberFormat vs toLocalString vs string split & reduce (with fraction digits)

Script Preparation code:

function pricize (num, decimal = 0) {
  const intPart = Math.floor(num)
  const intPieces = intPart.toString().split('')
  const len = intPieces.length
  const intStr = intPieces.reduce((result, chr, index, array) => {
    const pos = len - index
    result += (index !== 0 && pos % 3 === 0) ? ',' + chr : chr
    return result
  }, '')

  const decStr = decimal > 0
    ? num.toFixed(decimal + 1).toString().slice(-(decimal + 2), -1) // toFixed() は四捨五入してしまうので(decimal + 1)桁まで求めて切り取る
    : ''

  return intStr + decStr
}

var target = 123456789.123456789
var options = {minimumFractionDigits: 3, maximumFractionDigits: 3}

Tests:

toLocaleString
var a = target.toLocaleString('en-US', options);
Intl.NumberFormat
var a = new Intl.NumberFormat('en-US', options).format(target)
string split & reduce
var a = pricize(target, 3)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toLocaleString
Intl.NumberFormat
string split & reduce

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's dive into the benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that compares three different approaches for formatting numbers with fractional digits:

1. **toLocaleString**: A built-in method for converting a number to a string, suitable for most use cases.
2. **Intl.NumberFormat**: An internationalization API for formatting numbers according to the user's locale and preferences.
3. **string split & reduce**: A custom implementation using JavaScript's `split()` and `reduce()` methods.

**Options being compared**

The benchmark compares two options within each approach:

* For **toLocaleString**, only the locale is specified (en-US).
* For **Intl.NumberFormat**, two options are specified:
	+ `minimumFractionDigits: 3` (minimum number of digits to display after the decimal point)
	+ `maximumFractionDigits: 3` (maximum number of digits to display after the decimal point)

**Pros and Cons**

Here's a brief summary of each approach:

1. **toLocaleString**:
	* Pros:
		+ Simple and efficient
		+ Built-in method, so no additional dependencies required
	* Cons:
		+ May not produce consistent results across different locales or browsers
2. **Intl.NumberFormat**:
	* Pros:
		+ Provides more control over formatting options (e.g., locale, style)
		+ Can handle complex number formats (e.g., currency symbols, negative numbers)
	* Cons:
		+ Requires internationalization support in the browser
		+ May be slower due to the additional overhead of the API
3. **string split & reduce**:
	* Pros:
		+ Provides fine-grained control over formatting options (e.g., decimal places, thousand separators)
		+ Can be optimized for performance
	* Cons:
		+ Requires custom implementation and maintenance
		+ May not handle complex number formats or locale-specific issues

**Library: Intl.NumberFormat**

The `Intl.NumberFormat` API is part of the ECMAScript Internationalization API (ECMA-402). It provides a way to format numbers according to the user's locale and preferences. The API allows specifying various formatting options, such as:

* Locale: specifies the language and country code for formatting
* Style: specifies the formatting style (e.g., compact, long)
* Numbering System: specifies the numbering system (e.g., decimal, hexadecimal)

**Special JS feature or syntax**

There is no special JavaScript feature or syntax used in this benchmark. The focus is on comparing different approaches to formatting numbers.

**Other alternatives**

If you need to format numbers in a more complex way, you might consider using other libraries or APIs, such as:

* ** moment.js**: A popular library for working with dates and times.
* **numeral.js**: A lightweight library for formatting numbers according to specific styles (e.g., currency, percentage).
* **format.js**: A flexible library for formatting numbers and dates.

Keep in mind that each of these alternatives has its own strengths and weaknesses, and the choice ultimately depends on your specific use case and requirements.

Related benchmarks:

Intl.NumberFormat vs toLocalString vs string split & reduce (with fraction digits) (version: 0)

Comparing performance of: toLocaleString vs Intl.NumberFormat vs string split & reduce

Created: 5 years ago by: Guest

Jump to the latest result

toLocaleString

Intl.NumberFormat

string split & reduce

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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