从数组中读取数组数据

Alright so I am trying to achieve something but I am not sure how to do it. I am basically trying to read From-To array. Basically lets say that this is my array

$arr = array("a","b","c","d","e","f");

    foreach($arr as $a) {
        echo $a;
    }

I want to be able to read stuff from B to E. How do I achieve that?

Also I'd want to be able to reverse that, so for example I read from F to C (it would then show F,E,D,C)

I googled a bit but couldnt find any matching results for this.

EDIT: I am not trying to ask how to print all values from an array, I am asking how to reverse them, so I can for example read from 9th element to 1st element of the array

demo here

if you want to output the upper char use strtoupper() function and array_map() function.

<?php
$arr = array("a","b","c","d","e","f");
array_walk(array_slice($arr, 1, count($arr)-2), function($value){echo $value."
";});
array_walk(array_slice(array_reverse($arr), 0, count($arr)-2), function($value){echo $value."
";});