php函数没有看到参数的值

I have a php function in codeignter set up to run a query based on all the values it is given. By default, it's set up in my model like so:

function get_news($page=0, $limit=4, $offset=0, $name=0) {
    if($name == 0) {
        $query = $this->db->get('table', $limit, $offset);
    } else {
        $query = $this->db->get_where('table', array('name'=>''.$name.''), $limit, $offset);
    }
}

However when I pass a value for $name in my controller, it runs the query for $name==0

$name = "Bob";
$this->News_model->get_news($page=0, $limit=3, $offset=0, $name);

Any idea why the $name value isn't going through?

Model

function get_news($page=0, $limit=4, $offset=0, $name=0) {
  if($name == 0) {
    $query = $this->db->get('table', $limit, $offset);
  } else {
    $query = $this->db->get_where('table', array('name'=>$name), $limit, $offset);
  }
}

use

$name = "Bob";
$this->News_model->get_news(0, 3, 0, $name);