Revision b26f54f7-6be6-4437-a480-9dd2e87eaad1 - Code Golf Stack Exchange

PHP4 (48 chars)
-
Given *$argv[1]* as a [command line](https://www.php.net/manual/en/features.commandline.php) argument :
```php
echo preg_replace('#(.)(.)\b#','2ドル1ドル',$argv[1]);
```

PHP7.4 (48 chars)
-
The function **$f** is inverting the last two chars of every word :

```php
$f=fn($s)=>preg_replace('#(.)(.)\b#','2ドル1ドル',$s);
```
[Try it Online](https://tio.run/##hZFBSwMxEIXP7q8Y08BmoQh6rVspVOmhp9KLIEjczG5C0yRMUqu/fs3u6kGQGt5lmO/NYyZBh/7@IehQ8IQxRahBEslPUbC9li4eGPz36iWM7CGyecGe/QkJzmgbj0d22ZVZwok94mDeaxMhSzqQIVhkFyOjgSwnBxbt4H@yJgTTOdhiyusQrMiflGN/@SfWdRNLcWSdGsakDYJfK2j0amsfHXZwNjpBPOcghWDH4Ts2jkm4Aa/WP2yX9zFJTyyqid0Nl6kWPW/r1gkeq3oZCLtXwmBlg6KciZsq6@VtVs5Lfsdvy3mmFn3rCWWjxfffyAi8M@/ohmSOHwGbhKoqrkwLgrdialZwXf/qXimDgiGRJ1YtirEKMkZUuey/AA) - Usage :
```php
echo $f('Flippign Lettesr Aroudn');
```
Both versions are using 🐘's [PCRE](https://www.php.net/manual/en/intro.pcre.php) Text Processing Functions.

**Info**: Support for [PHP4](https://www.php.net/manual/php4.php) has been discontinued since 2008 but same code still works in PHP8.1.

[Mathematica](https://www.wolfram.com/language/) (58 chars)
-
```Mathematica
f=StringReplace[#,RegularExpression["(.)(.)\\b"]:>"2ドル1ドル"]&
```
[Try it online](https://tio.run/##nc8xC8IwEAXg3V9xxCIKIugoKBRUHDpIdZGaIaZnE0yTkKTUf1@Liw5Wio@33se7kgWBJQuSs6a5rY7BSV2kaBXjmA2nKRaVYm77sA69l0ZnZDybtL1croQu1yRaRHNCR82hvQuQwTu3jJwE0/5OKPQOHXyFzqZCBzUqbrDs5XVAJyE9tGUamLUKCdD/oJ2S1spCQ4IhoHcQO1Pl@ofXAYU9gtnkwEWcqK3GAmopAvi63ZcjqBeffv5Mmyc)