php - Set and Check two bit flags -

what want do:

have 4 conditions. maximum 2 set. there maximal 4 valid combinations.

$types = array(     "a" => 0x1,     "b" => 0x2,     "c" => 0x4,     "d" => 0x8, );

we can have a/b + c/d (=ac, ad, bc, bd)

$flags = $types["a"] | $types["c"];     if ($flags & ($types['a'] | $types['d']))      echo "true"; else     echo "false";  // output: "true"

okay i'm fiddling around .. way long.

how set , check 2 flags correctly?

// pseudo code explanation x = + d if(x = a+c)

Remember