Online PHP editor | output for U6c4K

<?php function displayUniquePhones($phone) { $output = []; foreach($phone AS $type => $number) { if($number != null) $output[$number][] = $type; } foreach($output AS $number => $types) { echo $number . " (" . implode(",",$types) . ")\n"; } } // Case 1 echo "CASE 1:\n"; displayUniquePhones([ 'h' => '212-555-1212', 'o' => '212-555-1212', 'm' => '212-555-1212' ]); // Case 2 echo "\n\nCASE 2:\n"; displayUniquePhones([ 'h' => '212-555-1212', 'o' => '212-555-1234', 'm' => '212-555-1212' ]); // Case 3 echo "\n\nCASE 3:\n"; displayUniquePhones([ 'h' => null, 'o' => '212-555-1234', 'm' => '212-555-1212' ]);