How can I display an array in a human readable format?

Question

If I have an array that looks like this:

$str = '';
if( $_POST['first'] )
    $str = $_POST['first'];
if( $_POST['second'] )
    $str .= ($str != '' ? ',' : '') . $_POST['second'];
if( $_POST['third'] )
    $str .= ($str != '' ? ',' : '') . $_POST['third'];
if( $_POST['fourth'] )
    $str .= ($str != '' ? ',' : '') . $_POST['second'];
$str .= ($str != '' ? '.' : '');

Which gives me something like this:

Joe, Adam, Mike.

However, I would like to add an "and" before the last item.

So it would then read:

Joe, Adam, and Mike.

How can I modify my code to do this?

Answer 1

Arrays are awesome for this:

$str = array();
foreach (array('first','second','third','fourth') as $k) {
    if ($_POST[$k]) {
        $str[] = $k;
    }
}
$last = array_pop($str);
echo implode(", ", $str) . " and " . $last;

You should probably special case the above for when there's one item. I, in fact, wrote a function called "conjunction" which does the above, and includes the special case:

function conjunction($x, $c="or")
{
    if (count($x) <= 1) {
        return implode("", $x);
    }
    $ll = array_pop($x);
    return implode(", ", $x) . " $c $ll";
}

Nice question!

Updated: General purpose way to do this:

function and_form_fields($fields)
{
     $str = array();
     foreach ($fields as $k) {
         if (array_key_exists($k, $_POST) && trim($_POST[$k])) {
              $str[] = $k;
         }
     }
     return conjunction($str, "and");
}

...

and_form_fields(array("Name_1","Name_2",...));

I added correct $_POST checking to avoid notices, and blank values.

Answer 2

The first ideea that comes to my mind is to always keep a last one name in an auxiliar variabile. When you have another one to put in, you take it put the 'comma' and get the next name in the aux.

At the end, when you finished added the names, you add 'and' and the last name from aux.

Answer 3

Instead of posting each as a separate variable, why not post them as an array:

#pull the array from the POST:
$postedarray = $_POST['names'];

#count the number of elements in the posted array:
$numinarray = count($postedarray);

#subtract 1 from the number of elements, because array elements start at 0
$numinarray = $numinarray -1;

#set a prepend string
$prependstr = "and ";

#Pull the last element of the array
$lastname = $postedarray[$numinarray];

#re-define the last element to contan the prepended string
$postedarray[$numinarray] = "$prependstr$lastname";

#format the array for your requested output
$comma_separated = implode(", ", $postedarray);

print "$comma_separated";