<?php
class Foo {}
class Bar extends Foo {}
var_dump(is_subclass_of(Bar::class, Foo::class));
var_dump(is_a(Foo::class, Foo::class));
var_dump(is_a(Foo::class, Bar::class));
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
bool(true)
bool(false)
bool(false)