Match data between two arrays

I have two arrays as such:

$cats=array(
	'wedding-venues'=>array('1', '2', 'Wedding Venues'),
	'wedding-caterers'=>array('1', '3', 'Wedding Caterers'),
);

$subcats=array(
	'banquet-halls'=>array('wedding-venues', 'Banquet Halls'),
	'hotels'=>array('wedding-venues', 'Hotels'),
	'general-caterers'=>array('wedding-caterers', 'Wedding Caterers'),
);

Code (markup):

And I have created a foreach loop which is meant to match $subcats to $cats:

foreach($subcats as $index => $value)
{
	if($value[0]==array_keys($cats))
	{
		//print out the matching values;
	}
}

Code (markup):

But this doesn't seem to work. Anyone got any ideas how to do this? It should just be as simple as that, but I can't figure out why that won't work!

 

Array_keys will create a array of keys, so you are comparing string to array.


foreach($subcats as $index => $value)
{
echo $value[0]."<br>";
echo array_keys($cats)."<br>";
if($value[0]==array_keys($cats))
{
//print out the matching values;
}
}

This will output:
wedding-venues
Array
wedding-venues
Array
wedding-caterers
Array

 

So then how do I do it?

 

foreach($subcats as $value)
{
	foreach($cats as $donkey){
                    
                 if($value == $donkey){
                         $match[] = value;
                 }

        }
        foreach($match as $val){ print $val }
}

PHP:

??