Question

Say i am having set of rows in a table and each row is having a column called city with some values assigned to it
iam iterating through the result set and i need to assign the list of city values of each row in to an array only unique

     foreach($res as $row){
       $cities =array();
       $cities[] = $row['city'];
       //when i say 
       var_dump($cities);
       //Iam not able to get array .how do i do that 
       $maincities = array('A','B',C)
     }

Answer 1

You’re resetting $cities to a new array for each row you loop through. Better would be:

$cities = array();
foreach ($res as $row)
{
    if ( ! in_array($row['city'], $cities)) {
        $cities[] = $row['city'];
    }
}