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I'm wondering before I attempt to refactor my page if its possible to have a double nested input array in html. I have an 8X5 group of elements in a form and it would be nice for me to be able to parse it using an array of arrays...something like

    <input type="text" name="list[][]" /><input type="checkbox" name="list[][]" />

and so on

Matt Phillips
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2 Answers2

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You are going to need to supply indexes into the first part of each field or else there is nothing to nest, and if it did work, it wouldn't look like a grid on the other end:

Row 1:

 name="list[0][]"

Row 2: 

 name="list[1][]"

etc.

Finally, your server needs to support this as PHP and Rails do out of the box. I am not sure about other server technologies. For an example, the following HTML when posted to PHP:

<form action="post.php" method="POST" accept-charset="utf-8">
  <input type="text" name="list[0][]" value="1" />
  <input type="text" name="list[0][]" value="2" />
  <input type="text" name="list[0][]" value="3" />

  <input type="text" name="list[1][]" value="4" />
  <input type="text" name="list[1][]" value="5" />
  <input type="text" name="list[1][]" value="6" />

  <input type="text" name="list[3][]" value="7" />
  <input type="text" name="list[3][]" value="8" />
  <input type="text" name="list[3][]" value="9" />

  <input type="submit" name="Send" value="Send" id="Send" />
</form>

If in the PHP the following code exists:

<?php print_r($_POST['list']); ?>

The output is:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
        )

    [1] => Array
        (
            [0] => 4
            [1] => 5
            [2] => 6
        )

    [3] => Array
        (
            [0] => 7
            [1] => 8
            [2] => 9
        )

)
Doug Neiner
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    So you are just giving the fields names that have a number. You are faking the functionality, it's not really supported by HTML4. – Esteban Küber Dec 30 '09 at 06:16
  • so what if i am? I'm just trying to make it a little more elegant to do my php code on the other end of the form :) – Matt Phillips Dec 30 '09 at 06:20
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    I updated my answer to provide an example in PHP. @voyager, I am not really faking anything since the fields are valid HTML4 names and its up to the server technology to support it. – Doug Neiner Dec 30 '09 at 06:22
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    @Doug Neiner: What I tried to say was that HTML doesn't have a native way of sending a multidimensional array, you have to fake it by either pickleing it into one variable or using one variable per dimension. – Esteban Küber Dec 30 '09 at 06:31
  • Is there any possibility to do same in ASP.NET MVC? or is there any other alternatives? – Keyur Mistry Nov 27 '15 at 06:48
  • Can you use strings instead of numbers inside the `[]`? – CMCDragonkai Aug 09 '17 at 09:32
1

HTML allows you to have several inputs with the same name, which are sent to the server through POST or GET as a comma separated array, which most (all?) server side languages recognize as a native array.

There is no native way of making a multidimensional array with pure HTML without you rolling something yourself with javascript.

Esteban Küber
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  • PHP does not recognize fields with the same name as an array. In fact, it will only return the last defined value. `d=1&d=2&d=3` when retrieved with `$_GET['d']` would return `"3"` – Doug Neiner Dec 30 '09 at 06:24
  • @Doug Neiner: I've never used PHP for anything bigger than a `hello, world`, so I assumed it worked like ASP, Python, Ruby and (I think) Perl. – Esteban Küber Dec 30 '09 at 06:28