Bogdan Ungureanu

I was working recently on a small feature that needed to output numbers like 1200 to a short compact version like 1.2k. Simple right? I can just make a function or use ChatGPT to generate one for me:

function formatCompactNumber($number, $decimals = 1) {
    if ($number >= 1000000) {
        return number_format($number / 1000000, $decimals) . 'M';
    } elseif ($number >= 1000) {
        return number_format($number / 1000, $decimals) . 'k';
    } else {
        return (string)$number;
    }
}

Task done. Except…

It’s not-so-straightforward if you need the value to be locale aware. For starters, the suffix needs to be translated and the decimal separator also needs to be different depending on the language.

For example, for English, the value is 1.2K, but that’s not the case for French where it’s 1,2 k. Simple right? Nope. If you support Spanish, 1200 translates to 1,2 mil. Hmm… What about non-latin alphabets? Well, for Bulgarian is 1,2 хил. What about Chinese and Russian? You get the point and the list goes on and on.

If you go down that rabbit hole, you also need to be sure that you have these rules for every language your software supports.

How does JavaScript solve it?

JS has a class built-in called Intl.NumberFormat that supports a bunch of formatting types: standard, scientific, compact.

For our code we need to use the compact form, like this:

new Intl.NumberFormat("bg", {
  notation: "compact",
}).format(1200);
//
'1,2 хил.'

Simple, easy, and probably not worth writing a post for it.

In PHP it’s not so straightforward

PHP comes bundled with the Intl extension that offers a NumberFormatter class that should do the same thing: it offers a bunch of formatters for numbers: scientific, percent, currency, etc. Except it doesn’t have a compact form.

Turns out, the Intl extension is just a wrapper on top of Unicode ICU library, just like Javascript. It’s actually mentioned in the Intl intro page:

Internationalization extension (further is referred as Intl) is a wrapper for » ICU library, enabling PHP programmers to perform various locale-aware operations including but not limited to formatting, transliteration, encoding conversion, calendar operations, » UCA-conformant collation, locating text boundaries and working with locale identifiers, timezones and graphemes.

Well, according to ICU docs, the library actually supports two compact forms: long and short. So, in theory, PHP should support it as well. And… it actually does! If you pass a magic number (14) it does display the number in the short-compact format. Not only that, it’s working since PHP 5! PHP simply doesn’t expose it as a constant or in the docs.

<?php
$numberFormatter = new NumberFormatter('bg', 14);
echo $numberFormatter->format(1200) . PHP_EOL;
// 1,2 хил.

Since the change is trivial, I’ve opened a PR in the PHP repo that got merged and now NumberFormatter exposes two new constants:

• NumberFormatter::DECIMAL_COMPACT_SHORT
• NumberFormatter::DECIMAL_COMPACT_LONG

<?php
$numberFormatter = new NumberFormatter('bg', NumberFormatter::DECIMAL_COMPACT_SHORT);
echo $numberFormatter->format(1200) . PHP_EOL;

You can see it in action on 3v4l on PHP’s master branch and will probably be available with PHP 8.5.