Connection.php

<?php

private function pdo (): \PDO
  {
    return new \PDO("
      mysql:host={$this->config['host']};
      port={$this->config['port']};
      dbname={$this->config['dbname']}", 
      $this->config['user'], 
      $this->config['pass']);
  }

  public function connect ()
  {
    try {
      $pdo = $this->pdo();
      $pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
      $this->connection = $pdo;
    } catch (PDOException $e) {
      echo 'Connection failed: ' . $e->getMessage();
    }
  }