<?php

class connection {
    static protected $con;
    protected $data;

    public function __construct($data) {
        $this->def($data);
    }

    protected function def($data) {
        if (!is_array($data) or count($data) < 1) {
            return false;
        }

        $this->data['hostname'] = ($data['hostname'] != '' ? $data['hostname'] : '');
        $this->data['username'] = ($data['username'] != '' ? $data['username'] : '');
        $this->data['password'] = ($data['password'] != '' ? $data['password'] : '');
        $this->data['database'] = ($data['database'] != '' ? $data['database'] : '');
    }

    public function connect() {
        if (count($this->data) < 1) {
            return false;
        }

        self::$con = mysqli_connect(
                        $this->data['hostname'],
                        $this->data['username'],
                        $this->data['password'],
                        $this->data['database']
                    );
       return true;
    }
}

$class = new connection(array(
            'username' => '',
            'hostname' => '',
            'password' => '',
            'database' => ''
        ));
$class->connect();