Question

I have 2 arrays which might look something like this:

$a1 = array('c','b','a');
$a2 = array('a', 'b', 'c', 'd', 'e');

I need to somehow check whether every value in $a1 is present in $a2.

I’ve looked at array_diff and array_intersect but can’t see how they can be used because the only return the values that are present and not present respectively.

Answer 1

I am not sure what you mean by “present respectively” but array_diff is the function you are looking for. Just make sure you pass the arrays into the function in the correct order. Try:

// result = no
echo count( array_diff( $a1, $a2 ) ) ? 'yes' : 'no';
// result = yes
echo count( array_diff( $a2, $a1 ) ) ? 'yes' : 'no';