Unable to Retrieve data from PHP class
<p>In the following code I am getting error: <code>Undefined variable: base_url on line 27</code> and <code>Cannot access empty property on line 27</code>.</p>

<p>I need to echo  the parameter <code>http://google.com</code> passed in get_url() from render().</p>

<pre><code>&lt;?php

$smart_url = new smart();

$smart_url -&gt; get_url('http://google.com');

echo  $smart_url -&gt; render();


 /**
 * Smart URL
 */

class smart {

private $base_url;

/**
 * 
 * @param string $url
 */
public function get_url($url) {
        $this -&gt; $base_url = $url;

}


/**
 * @return string $base_url
 */
public function render() {
    return $this -&gt; $base_url;


}

}


?&gt;
</code></pre>
