<?php
class Name{
protected $first ;
public function setNameType($value) {
    $this->first = $value;
}
public function getNameType() {
    return $this->first;
}
}

$name = new Name;
$name->setNameType("My Name");
echo $name->getNameType();
?>

<?php
class Name{
protected $first ;
public function __construct($value) {
    $this->first = $value;
}
public function getNameType() {
    return $this->first;
}
}

$name = new Name("My Name");
echo $name->getNameType();
?>

class Book {

    public function __construct() {

        $registry  = RegistrySingleton::getInstance();
        $this->_database = $registry->database;

        // or

        global $databaseConnection;
        $this->_database = $database;
    }

}

class Book {

    private $_databaseConnection;

    public function __construct() { }

    public function setDatabaseConnection($databaseConnection) {
        $this->_databaseConnection = $databaseConnection;
    }

}

$book = new Book();
$book->setDatabase($databaseConnection);

$book = new Book($databaseConnection, $configFile);

$book = new Book();
$book->setDatabase($databaseConnection);
$book->setConfigFile($configFile);

class Container {

    public static $_database;

    public static function makeBook() {

        $book = new Book();
        $book->setDatabase(self::$_database);
        // more injection...

        return $book;
    }

}

$book = Container::makeBook();