array of checkboxes

TheSeeker

i have to arrays of checkboxes on a form

like this
<form blah blah blah...post to some phppage.php>
<INPUT id='check1' type=checkbox name=checkbox1 value='1'>
<INPUT id='check2' type=checkbox name=checkbox1 value='2'>
<INPUT id='check3' type=checkbox name=checkbox1 value='3'>
<INPUT id='checkN' type=checkbox name=checkbox1 value='N'>

</form>

how do i loop through
the 2 arrays on the php page that i send this form to????

AQHost

Hi,

You'd be better off actually creating the array in the form like this:

<form blah blah blah...post to some phppage.php> 
<INPUT id='check11' type=checkbox name=checkbox1[] value='1'> 
<INPUT id='check12' type=checkbox name=checkbox1[] value='2'> 
<INPUT id='check13' type=checkbox name=checkbox1[] value='3'> 
<INPUT id='check1N' type=checkbox name=checkbox1[] value='N'> 

<INPUT id='check21' type=checkbox name=checkbox2[] value='1'> 
<INPUT id='check22' type=checkbox name=checkbox2[] value='2'> 
<INPUT id='check23' type=checkbox name=checkbox2[] value='3'> 
<INPUT id='check2N' type=checkbox name=checkbox2[] value='N'> 
</form>

The [] cause an array to be constructed dynamically in the form. When you POST the form this will give your script two arrays: $POST[checkbox1] and $POST[checkbox2] which you can loop through as follows:

$checkbox1array = $_POST[checkbox1];
$checkbox2array = $_POST[checkbox2];
foreach($checkbox1array as $key => $value)
{
   Do interesting stuff;
}
foreach($checkbox2array as $key => $value)
{
   Do interesting stuff;
}

Hope this helps,
Simon.

Sxooter

Actually, in this situation, the names should be:

<checkbox name=checkbox[1] value=0
<checkbox name=checkbox[1] value=1
<checkbox name=checkbox[1] value=2
<checkbox name=checkbox[1] value=n

<checkbox name=checkbox[2] ...
<checkbox name=checkbox[1] ...
<checkbox name=checkbox[1] ...
<checkbox name=checkbox[1] ...

Cause they look like radio buttons. I.e. all the same value, only one can be selected.

but if you HAVE to parse a form someone else made that looks like the original, you can use named vars to do it:

for ($i=0;$i<2;$i++){
  $varname=checkbox.$i;
  print $varname." is ".$$varname."<BR>";
}

netizen

Originally posted by Sxooter
Actually, in this situation, the names should be:

<checkbox name=checkbox[1] value=0
<checkbox name=checkbox[1] value=1
<checkbox name=checkbox[1] value=2
<checkbox name=checkbox[1] value=n

<checkbox name=checkbox[2] ...
<checkbox name=checkbox[1] ...
<checkbox name=checkbox[1] ...
<checkbox name=checkbox[1] ...

Cause they look like radio buttons. I.e. all the same value, only one can be selected.

but if you HAVE to parse a form someone else made that looks like the original, you can use named vars to do it:
for ($i=0;$i<2;$i++){
  $varname=checkbox.$i;
  print $varname." is ".$$varname."<BR>";
}
[/B]

I'm afraid the way you declared the name value would unfortunately return invalid values if multiple items were selected. Check boxes allow multiple selections.

For example. If I chose value 0 for option set 1 and then chose value 1 for set 2, then the returning value would be $checkbox[1] = 1 and only that, because the variable $checkbox[1] would be overwritten.

AQHost's solution is the correct way to handle form arrays.

Sxooter

Like I said, I had the feeling he was processing radio buttons, not checkboxes. You're right, for checkboxes, you need them to be unique. I use this kinda naming:

<checkbox name=cb[0][] value=0>
<checkbox name=cb[0][] value=1>
<checkbox name=cb[0][] value=2>
<checkbox name=cb[0][] value=n>

<checkbox name=cb[1][] value=0>
<checkbox name=cb[1][] value=1>
<checkbox name=cb[1][] value=2>
<checkbox name=cb[1][] value=n>

then you can just walk the array by number. Since a lot of times the checkboxes are made from a static arrya like

$checkboxnames = array("stan","laurel","hardy");

You already know the position in the array and all.

Thanks for the catch.