How do I get the values from array of array?

I have array like below:

Array
开发者_StackOverflow(
    [_edit_lock] => Array
        (
            [0] => 1309611144:1
        )

    [_edit_last] => Array
        (
            [0] => 1
        )

    [banner_url] => Array
        (
            [0] => http://apptivowp.apptivo.com/awp-content/10001/uploads/2011/07/gallery_banner.jpg
        )

    [_yoast_wpseo_focuskw] => Array
        (
            [0] => 
        )

    [_yoast_wpseo_title] => Array
        (
            [0] => 
        )
)

How can I get the banner_url value?

As simple as:

$array['banner_url'][0]