How to merge two arrays by taking over only values from the second array that has the same keys as the first one?

Question

I\'d like to merge two arrays with each other:

$filtered = array(1 => \'a\', 3 => \'c\');
$changed = array(2 => \'b*\', 3 => \'c*\');
         


        

Answer 1

if you want the second array ($b) to be the pattern that indicates that if there is only the key there, then you could also try this

$new_array =  array_intersect_key( $filtered, $changed ) + $changed;