yes for using $num = $num++; yes !!!!!! "Ashley Sheridan" <a...@ashleysheridan.co.uk> wrote in message news:1254577641.2385.7.ca...@localhost... > 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_def...@yahoo.de > > > > <clanc...@cybec.com.au> wrote in message > > news:8fudc5tc6qvfj4n297kvjlqd3s7sjdk...@4ax.com... > > > 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 > > >
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