<?php
interface A {}
class B implements A {}
class C {}
var_dump(in_array(A::class, class_implements(A::class)));
var_dump(in_array(A::class, class_implements(B::class)));
var_dump(in_array(A::class, class_implements(C::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(false)
bool(true)
bool(false)