Question

I have user inputs as follows:

<form action="special.php" method="post">
    <input name="first1"> <input name="last1"> <input name="age1">
    <input name="first2"> <input name="last2"> <input name="age2">
    <input name="first3"> <input name="last3"> <input name="age3">
    <input name="first4"> <input name="last4"> <input name="age4">
    <input name="first5"> <input name="last5"> <input name="age5">
    <input name="first6"> <input name="last6"> <input name="age6">
    ...

    N
</form>

The amount of user inputs in the form is determined by the user; meaning, the user can add 5,10,20 additional lines to the code above, creating new input elements (following the pattern above) as they fit.

My question is, once the form gets submitted, what is an easy way to iterate and print out all the SET POST variables?

Something like:

for($i=0; $i < $numPostVars; $i++){
   if(isset($_POST['first".$i."'])){
       //echo all first names post variables that are set
    }
}

// do the same from last names & age in separate loops

Answer 1

Inputs can be treated as arrays with a syntax very similar to that used in PHP:

<input name="name[1]" value="value 1">
<input name="name[2]" value="value 2">

This would result in a $_POST['name'] that looks like this:

array(
  1 => "value 1",
  2 => "value 2"
);

This principle can be expanded to incorporate multi-dimensional and associative arrays. So if you were to name your inputs like this:

<input name="rows[1][first]"> <input name="rows[1][last]"> <input name="rows[1][age]">
<input name="rows[2][first]"> <input name="rows[2][last]"> <input name="rows[2][age]">

…you would be able to easily iterate over $_POST['rows'] with a foreach construct. The data structure will be very similar to a set of database results.

foreach ($_POST['rows'] as $row) {
  // do stuff with $row['first'], $row['last'] and $row['age'] here
}

A couple of things to note:

• Unlike PHP, associative array keys in HTML do not require quotes, and using them will produce a result you may not expect. It will work, but not in the way you might think. You still need to use quotes in PHP though.
• As far as I am aware, this syntax is not a W3C standard. PHP, however, always handles it as expected.