associativity

    The property of an operator that says whether
   a sequence of three or more expressions combined by the
   operator will be evaluated from left to right (left
   associative) or right to left (right associative).  For
   example, in Perl, the lazy and operator && is left
   associative so in the expression:

     $i >= 0 && $x[$i] >= 0 && $y[$x[$i]] == 0

   the left-most && is evaluated first, whereas = is right
   associative, so in

     $a = $b = 42

   the right-most assignment is performed first.

   (2007-06-16)