Introduced in PHP 7: IntlChar class containing static methods for characters

Code
<?php

dump
(
    
IntlChar::toupper('ä'),
    
IntlChar::tolower('Č'),
    
IntlChar::totitle('f'),

    
IntlChar::isUUppercase('A'),
    
IntlChar::isULowercase('A'),
    
    
IntlChar::charName('Ü'),
    
    
IntlChar::isdigit(3),
    
IntlChar::isdigit('3'),
    
IntlChar::isdigit(0xFF),
    
IntlChar::isdigit(0b01),
    
    
"\u{2603}"
);
Result
^ "Ä"

^ "č"

^ "F"

^ true

^ false

^ "LATIN CAPITAL LETTER U WITH DIAERESIS"

^ false

^ true

^ false

^ false

^ ""
Used Versions
PHP 8.0, Laminas MVC 3.2, Symfony 5.2, Laravel 8.28, PHPUnit 9.5, Doctrine ORM 2.8