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Posted by Matthew Weier O'Phinney on 06/07/05 00:07
* Merlin <news.groups@web.de> :
> Matthew Weier O'Phinney wrote:
> > * Merlin <news.groups@web.de> :
> > > I am outputting an multidim. array. That works fine, except one thing. The first
> > > letter of the value inside dimension 1 always gets printed.
> > >
> > > For example:
> > >
> > > I fill the arrays:
> > > while ($row = mysql_fetch_object($result)){
> > > $cat[$row-> main_id][name] = $row-> main_name;
> > > $cat[$row-> main_id][$row-> sub_id][name] = $row-> sub_name;
> > > }
> >
> > First off, if you're creating associative arrays, you should quote the
> > keys:
> >
> > $cat[$row-> main_id]['name'] = $row-> main_name;
> >
> > If you don't do so, PHP assumes you're using a constant value for the
> > key name.
> >
> > > Then I output them:
> > > foreach ($cat AS $maincat){
> > > echo $maincat[name].':';
> >
> > Quote your keys!
> >
> > > foreach($maincat AS $subcat){
> >
> > You do realize that the above will also loop over the index 'name',
> > right?...
> >
> >
> > > echo $subcat[name].$br;
> >
> > and since it does, the first element in that array is 'name', which
> > isn't an array, but a string. Since the 'name' constant isn't defined,
> > it will interpret that as 'true', or 1, and so it takes the first
> > character of that string.
> >
> >
> > > }
> > > echo $br;
> > > }
> > >
> > > Which does result in:
> > >
> > > Europe:E
> > > Germany
> > > UK
> > >
> > > North America:N
> > > US
> > > CA
> > >
> > > As you can see I get the extra letters N and E. Is this an php error or did I do
> > > something wrong?
> >
> > So, what you should probably do is create an additional layer in your
> > multi-dimensional array for the subcategories, and have it of the form
> > sub_id => sub_name:
> >
> > $cat[$row-> main_id]['subs'][$row-> sub_id] = $row-> sub_name;
> >
> > Then loop over that:
> >
> > foreach ($cat as $main_cat) {
> > echo $maincat['name'] . ":\n";
> > foreach ($maincat['subs'] as $sub_id => $sub_name) {
> > echo "$sub_name$br"; // could also use $sub_id here if
> > // desired
> > }
> > }
> >
>
> This is very helpful and does work. However I did not understand it completley.
> What if I want to add another value, for example name2 or name3.
> It looks like this example is limited to id and name.
> Could I just add:
> $cat[$row-> main_id]['subs'][$row-> sub_id] = $row-> name2;
>
> Guess not. Can you tell me how to add other fields to the array?
You should probably do some studying up on multidimensional and/or
nested arrays so you can get a better handle on this stuff.
If you need to be able to add multiple names for a sub_id, do it as an
array:
$cat[$row->main_id]['subs'][$row->sub_id][] = $row->name1;
$cat[$row->main_id]['subs'][$row->sub_id][] = $row->name2;
$cat[$row->main_id]['subs'][$row->sub_id][] = $row->name3;
However, this will break your loop above -- you'll need another layer of
looping added in:
foreach ($cat as $main_cat) {
echo $maincat['name'] . ":\n";
foreach ($maincat['subs'] as $sub_id => $names) {
foreach ($names as $name) {
echo "$name$br"; // could also use $sub_id here if
// desired
}
}
}
Hope that helps.
--
Matthew Weier O'Phinney | WEBSITES:
Webmaster and IT Specialist | http://www.garden.org
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802-863-5251 x156 | http://nationalgardenmonth.org
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