On Sat, 2009-10-03 at 15:46 +0200, Ralph Deffke wrote: > yes for using > $num = $num++; > yes !!!!!! > > "Ashley Sheridan" <ash@xxxxxxxxxxxxxxxxxxxx> wrote in message > news:1254577641.2385.7.camel@xxxxxxxxxxxx > > On Sat, 2009-10-03 at 15:33 +0200, Ralph Deffke wrote: > > > u increment after! asigning, so far so good, but for math reasons the > > > interpreter has to keep in mind the 123 you want to assign before > increment > > > to the same var. > > > > > > this is absolutely correct what php does here. > > > > > > $num = ++$num; would print 124 > > > the same like > > > $num++; > > > > > > on the other hand this is just bullshit I would release any programmer > using > > > that type of code. > > > > > > ralph_deffke@xxxxxxxx > > > > > > <clancy_1@xxxxxxxxxxxx> wrote in message > > > news:8fudc5tc6qvfj4n297kvjlqd3s7sjdkvqb@xxxxxxxxxx > > > > Daevid Vincent is surprised that: > > > > > > > > $num = 123; > > > > $num = $num++; > > > > print $num; //this prints 123 and not 124 ?!! > > > > > > > > To me this is relatively logical. As I understand it, the > post-increment > > > operator says "do > > > > something with the variable, and then increment it. The trouble in > this > > > case is that we > > > > are doing something irrational; we are copying the number back to > itself, > > > and to me it is > > > > reasonably logical (or at least no less illogical than the > alternative) to > > > assume that if > > > > we copy it to itself, then increment the original version, the copy > will > > > not be > > > > incremented. > > > > > > > > However there is one feature of PHP which, to my mind, is really bad > > > design. How many of > > > > you can see anything wrong with the following procedure to search a > list > > > of names for a > > > > particular name? > > > > > > > > $i = 0; $j = count ($names); while ($i < $j) > > > > { if ($names[$i] == $target) { break; } > > > > ++$i; > > > > } > > > > > > > > As long as the names are conventional names, this procedure is > probably > > > safe to use. > > > > However if you allow the names to be general alphanumeric strings, it > is > > > not reliable. One > > > > of my programs recently broke down in one particular case, and when I > > > eventually isolated > > > > the bug I discovered that it was matching '2260' to '226E1'. (The > logic of > > > this is: 226E1 > > > > = 226*10^1 = 2260). > > > > > > > > I agree that I was well aware of this trap, and that I should not have > > > used a simple > > > > comparison, but it seems to me to be a bizarre design decision to > assume > > > that anything > > > > which can be converted to an integer, using any of the available > > > notations, is in fact an > > > > integer, rather than making the default to simply treat it as a > string. It > > > is also a trap > > > > that it is very easy to fall into if you start off thinking about > simple > > > names, and then > > > > extend (or borrow) the procedure to use more general strings. > > > > > > > > And can anyone tell me whether, in the above case, it is sufficient to > > > write simply: > > > > if ((string) $names[$i] == $target), > > > > > > > > or should I write: > > > > if ((string) $names[$i] == (string) $target)? > > > > > > > > (I decided to play safe and use strcmp ().) > > > > > > > > > > > > > > > You'd release a programmer for using the incremental operators for self > > assignation? > > > > Thanks, > > Ash > > http://www.ashleysheridan.co.uk > > > > > > > > > To be honest, of all the programming sins, this is not one to fire someone for. Have a look at the daily wtf and you'll see what i mean! Thanks, Ash http://www.ashleysheridan.co.uk
