get first and last element in array

I have this array:

array(1) {
 ["dump"]=>
 string(38) "["24.0",24.1,24.2,24.3,24.4,24.5,24.6]"
}

my question:how to get the first and the last element out from this array, 

so i will have:

$firstEle = "24.0"; and  $lastEle = "24.6";

Solution:

<?php
 $array = array(24.0,24.1,24.2,24.3,24.4,24.5,24.6);

 $first = reset($array);
 $last = end($array);
 var_dump($first, $last);

?>