Online PHP editor | output for a4EI0

<?php // This stands in for stdClass for this demo, because class_alias doesn't work with built-in classes class myStdClass{} class UserDefinedClass{} class_alias('myStdClass', 'DynamicObject'); $ud_obj = new UserDefinedClass(); $do_obj = new DynamicObject(); $sc_obj = new myStdClass(); echo "===[get_class()]===\n"; printf( "UserDefinedClass Object Class: %s\n", get_class($ud_obj)); printf( "DynamicObject Object Class: %s\n", get_class($do_obj)); printf( "myStdClass Object Class: %s\n", get_class($sc_obj)); echo "\n===[gettype()]===\n"; printf( "UserDefinedClass Object Type: %s\n", gettype($ud_obj)); printf( "DynamicObject Object Type: %s\n", gettype($do_obj)); printf( "myStdClass Object Type: %s\n", gettype($sc_obj)); echo "\n===[is_a(stdClass::class)]===\n"; printf( "UserDefinedClass Object Type: %s\n", is_a($ud_obj,stdClass::class)); printf( "DynamicObject Object Type: %s\n", is_a($do_obj,stdClass::class)); printf( "myStdClass Object Type: %s\n", is_a($sc_obj,stdClass::class)); echo "\n===[instanceof stdClass]===\n"; printf( "UserDefinedClass Object Type: %s\n", $ud_obj instanceof stdClass); printf( "DynamicObject Object Type: %s\n", $do_obj instanceof stdClass); printf( "myStdClass Object Type: %s\n", $sc_obj instanceof stdClass); echo "\n===[is_a(DynamicObject::class)]===\n"; printf( "UserDefinedClass Object Type: %s\n", is_a($ud_obj,DynamicObject::class)); printf( "DynamicObject Object Type: %s\n", is_a($do_obj,DynamicObject::class)); printf( "myStdClass Object Type: %s\n", is_a($sc_obj,DynamicObject::class)); echo "\n===[instanceof DynamicObject]===\n"; printf( "UserDefinedClass Object Type: %s\n", $ud_obj instanceof DynamicObject); printf( "DynamicObject Object Type: %s\n", $do_obj instanceof DynamicObject); printf( "myStdClass Object Type: %s\n", $sc_obj instanceof DynamicObject); echo "\n===[is_subclass_of(stdClass::class)]===\n"; printf( "UserDefinedClass Object Type: %s\n", is_subclass_of($ud_obj,stdClass::class)); printf( "DynamicObject Object Type: %s\n", is_subclass_of($do_obj,stdClass::class)); printf( "myStdClass Object Type: %s\n", is_subclass_of($sc_obj,stdClass::class));