Transform a multidimensional array in php - php

Question

This loop
$demo = array();
for($i=0;$i<count($big_array);$i++){
echo 'Page['.$i.'][0]: '.$big_array[$i][0].'<br>';
for($j=1;$j<count($big_array[$i]);$j++){
echo 'Email['.$i.']['.$j.']: '.$big_array[$i][$j].'<br>';
$demo[$big_array[$i][$j]][] = $big_array[$i][$j-1]; //something is not ok with this
}
}
gives me this:
Page[0][0]: http://www.example.com/impressum
Email[0][1]: sales#example.com
Email[0][2]: support#example.com
Page[1][0]: http://www.example.com/termsofuse
Email[1][1]: support#example.com
Email[1][2]: terms1#example.com
Email[1][3]: terms2#example.com
Email[1][4]: ad2#example.com
Page[2][0]: http://www.example.com/adpolicy
Email[2][1]: support#example.com
Email[2][2]: ad1#example.com
Email[2][3]: ad2#example.com
Email[2][4]: ad1#example.com
How can I transform it to get this result:
sales#example.com
http://www.example.com/impressum
support#example.com
http://www.example.com/impressum
http://www.example.com/termsofuse
http://www.example.com/adpolicy
terms1#example.com
http://www.example.com/termsofuse
terms2#example.com
http://www.example.com/termsofuse
ad2#example.com
http://www.example.com/termsofuse
http://www.example.com/adpolicy
ad1#example.com
http://www.example.com/adpolicy
var_dump($big_array):
array ( 0 => array ( 0 => 'http://www.example.com/impressum', 1 => 'sales#example.com', 2 => 'support#example.com', ), 1 => array ( 0 => 'http://www.example.com/termsofuse', 1 => 'support#example.com', 2 => 'terms1#example.com', 3 => 'terms2#example.com', 4 => 'ad2#example.com', ), 2 => array ( 0 => 'http://www.example.com/adpolicy', 1 => 'support#example.com', 2 => 'ad1#example.com', 3 => 'ad2#example.com', 4 => 'ad1#example.com', ), )

Answer 1

$array = array ( 0 => array ( 0 => 'http://www.example.com/impressum', 1 => 'sales#example.com', 2 => 'support#example.com', ), 1 => array ( 0 => 'http://www.example.com/termsofuse', 1 => 'support#example.com', 2 => 'terms1#example.com', 3 => 'terms2#example.com', 4 => 'ad2#example.com', ), 2 => array ( 0 => 'http://www.example.com/adpolicy', 1 => 'support#example.com', 2 => 'ad1#example.com', 3 => 'ad2#example.com', 4 => 'ad1#example.com', ), );
print_r($array);
$final = array();
foreach ( $array as $group )
{
for ( $i=1; $i<count($group); $i++ )
{
$final[$group[$i]][] = $group[0];
}
}
print_r($final);
Here is the PHP Playground result.
To format it like your example:
foreach ( $final as $email => $links )
{
echo $email . "\n";
foreach ( $links as $link )
{
echo " " . $link . "\n";
}
}