Define a function called get_difference, which takes in the same as get_intersection  but it returns a new array that contains all the elements in $a that are not in $b. E.g. if $a is array(2, 5, 1, 7) and $b is array(1, 6, 2, 4), it returns array(5, 7).


function get_difference ($a,$b)
{
    $newArray=array();

    foreach($a as $v)

    {
        if(in_array($v,$b))
        {


        }
        else
        {
            $newArray[]=$v;

        }
    foreach($b as $w)

    {
        if(in_array($w,$a))
        {


        }
        else
        {
            $newArray[]=$w;

        }



    }
    }


    return $newArray;

}