计算从数组到php的总时数。

My array looks like this

数组是这样的

Array
(
    [0] => Array
        (
            [ltime] => 00:02:55
        )

    [1] => Array
        (
            [ltime] => 00:07:56
        )

    [2] => Array
        (
            [ltime] => 01:03:32
        )   

    [3] => Array
        (
            [ltime] => 01:13:34
        )

    [4] => Array
        (
            [ltime] => 02:13:44
        ) 

    [5] => Array
        (
            [ltime] => 03:08:53
        )

    [6] => Array
        (
            [ltime] => 03:13:54
        )      
)
Array
(