Pasar función de PHP 5.3.3 a PHP 7.1.1

[xfxstudios]

Prueba así:

Código PHP:

function __construct($host = DB_HOST,$user = DB_USER, $pass = DB_PASS, $dbname = DB_NAME ){
 
    $this->con = new mysqli($host, $user, $pass, $dbname);
        if ($this->con->connect_errno) {
            echo "Fallo al conectar a MySQL: (" . $this->con->connect_errno . ") " . $this->con->connect_error;
        }
 
    $this->con->set_charset("utf8");
}