Slightly harder Array Question (just learning)

Maryanne

Yesterday I learned "named capture groups" 🙂

To implement what I've learned, I have a 100% perfectly working preg_match_all which goes like this:

$result = 'big paragraph listing Main Part Number and their attributes (colors, weights, etc.)';
preg_match_all("/(?<Main_Number>\d{16}).*?\<td\>(?<origin>.*?)\<br\>(?<color>.*?)\./",$result,$matches);

The array "$matches" has the Main Numbers and their respective attributes all really separate from each other in groups (like a group of Main Numbers, a group of origins, and a group of colors).

Isn't there some way to actually "assign" those attributes to their respective Main Numbers? Maybe by somehow creating a brand new array out of the "$matches" array?

And, maybe this brand new array could be indexed on the Main Numbers.... so that echoing $Main_Number['origin'] would yield "USA".... or echoing $Main_Number['color'] would yield "GREEN?"

I've been trying to figure this out myself by doing things like

for($i=0;$i<count($matches['Main_Number']);$i++) {
$matches['Main_Number'] = $matches['origin'][$i],$matches['color'][$i],$matches['weight'][$i];
}

...but all I get are errors because I don't know what I'm doing :queasy:

Is there any way to create a new array indexed on "Main_Number" ?

Weedpacket

What you can do use use [man]preg_match_all[/man]'s [font=monospace]PREG_SET_ORDER[/font] flag to swap the indices in the [font=monospace]$matches[/font] array (the default is [font=monospace]PREG_PATTERN_ORDER[/font]). So that instead of [font=monospace]$matches['weight'][$i][/font] and the like you have [font=monospace]$matches[$i]['weight'][/font], i.e. [font=monospace]$matches[$i][/font] is a complete Main_Number/origin/color/weight group.
They're not indexed by [font=monospace]'Main_Number'[/font] yet though: that's just another element. So you want a new array and [man]foreach[/man] of those groups you want to put it in the new array using its [font=monospace]'Main_Number'[/font] as the index.

$indexed_by_main = array();
foreach($matches as $match)
{ // each $match is a Main_Number/origin/color/weight group
    $indexed_by_main[$match['Main_number']] = array($match['origin'], $match['color'], $match['weight']);
}

And in fact there might be some benefit in keeping [font=monospace]'Main_number'[/font] in the group even while still using it as an index. That would make the array being created in that loop identical to [font=monospace]$match[/font] anyway:

$indexed_by_main = array();
foreach($matches as $match)
{ // each $match is a Main_Number/origin/color/weight group
    $indexed_by_main[$match['Main_number']] = $match;
}

But now all the loop is doing is pulling out one "column" from the [font=monospace]$matches[/font] array. PHP has a function to do that, and you've already seen the function that can be used to combine it with another array.

$indexed_by_main = array_combine(array_column($matches, 'Main_number'), $matches);