Re: array key's: which is correct?

On Tue, 2010-06-08 at 10:35 -0400, Paul M Foster wrote: > On Tue, Jun 08, 2010 at 09:38:58AM -0400, Robert Cummings wrote: > > > Tanel Tammik wrote: > >> Hi, > >> > >> which one is correct or "better"? > >> > >> $array[3] = ''; > >> or > >> $array['3'] = ''; > >> > >> $i = 7; > >> > >> $array[$i] = ''; > >> or > >> $array["$i"] = ''; > > > > Sometimes it is good to illustrate the correct answer: > > > > <?php > > > > $array = array > > ( > > '1' => '1', > > '2' => '2', > > 'three' => 'three', > > '4.0' => '4.0', > > 5.0 => 5.0, > > ); > > > > var_dump( array_keys( $array ) ); > > > > ?> > > > > The answer is surprising (well, not really :) and certainly advocates > > against making literal strings of integers or manually converting a > > string integer to a real integer or using floating point keys. > > Curse you, Rob Cummings! ;-} > > I was stunned at the results of this. I assumed that integers cast as > strings would remain strings as indexes. Not so. And then float indexes > cast to ints. Argh! > > My advice to the original poster was slightly incorrect. But I would > still encourage you to avoid enclosing variables in double-quotes > unnecessarily. (And integers in single-quotes for that matter.) > > Paul > > -- > Paul M. Foster > The obvious way around this would be to include some sort of character in the index that can't be cast to an integer, so instead of $array[1.0] which would equate to $array[1] maybe add an underscore to make it $array['_1.0']. It's not the prettiest of solutions, but it does mean that indexes are kept as you intended, and you need only strip out the first character, although I imagine a lot of string manipulation on a large array would decrease performance. Thanks, Ash http://www.ashleysheridan.co.uk