// Get the first character of a string
$str = 'This is a test.';
$first = $str{0};  // $first = T;
// Get the third character of a string
$third = $str{2};  // $third = i;

// Get the last character of a string.
$str = 'This is still a test.';
$last = $str{strlen($str)-1};  // $last = t;

// Modify the last character of a string
$str = 'Look at the sea';
$str{strlen($str)-1} = 'e';  // $str = 'Look at the see';

$a = "86-0754-88888888-";
if ($a{strlen($a)-1} == "-")
    $a = substr($a,0,strlen($a)-1);
echo $a;