我想获取PHP数组中的下一个值,例如:
$array = array('a', 'b', 'c', 'd', 'e', 'f');
$current_array_val = 'c';
//so I want to run a code to get the next value in the array and
$next_array_val = 'd';
//And also another code to get the previous value which will be
$prev_array_val = 'b';
请问如何运行我的代码以实现这个功能。