Re: reason for a "Notice:.." on one site but not another? (Same code.)

This "intelligence" is given by the laziness of the && operator. $res = a() && b(); # if a() is false then b() does not evaluate $res = a() & b(); # b() evaluates no matter a()'s result so, order matters. On Mon, Aug 10, 2009 at 3:29 PM, Andrew Ballard <aballard@gmail.com> wrote: > On Mon, Aug 10, 2009 at 1:50 PM, Ralph Deffke<ralph_deffke@yahoo.de> > wrote: > > this is not "intelligence" its just pure math. the '&&' says > > if BOTH > > expressions are true then the whole expression is true. > > > > so if the first one is false, the whole is false, why checking the next > one > > in the underlaying C it would be something like this > > { > > if ( expression == false ) return false; > > if ( expression == false) return false; > > return true; > > } > > > > ralph > > ralph_deffke@yahoo.de > > That's logically correct, and while PHP does implement this > "short-circuit" logic, not all languages do. In that regard, I > appreciate what John meant by saying it makes it look "more > intelligent." Some languages evaluate each of the conditions to their > respective boolean results before evaluating the logical operators. > > Andrew > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > -- Martin Scotta