PHP/Class/Reflection Existance

class_exists: given a class name and check its existance

<?php
class Person {
    private $name;    
    private $age;    
    private $id;    
    function setId( $id ) {
        $this->id = $id;
    }
    
    function getId(){
        echo "get id method";    
    }
    
    function __clone() {
        $this->id = 0;
    }
}
$classname = "Person";
 
if ( ! class_exists( $classname ) ) {
    throw new Exception( "No such class as $classname" );
} 
$myObj = new $classname();
$myObj->getId();
?>

Define class helper class to check the method existance

<?php
class A {
    function getA( ) {
        return array( "A", "B" );
    }
}
class Helper {
    private $classA;
    function __construct( A $classA ) {
        $this->classA = $classA;
    }
    function __call( $method, $args ) {
        if ( method_exists( $this->classA, $method ) ) {
            return $this->classA->$method( );
        }
    }
}
$tool= new Helper( new A() );
print_r( $tool->getA() );
?>