RE: [PHP] Sorting a Two-Dimensional Array

If you havent worked it out you DONT want to write a file every time (csv) but you do want to use uasort() if the keys are meaningful or usort() if they are not. Mark Nold markn@alverstone.com.au Systems Consultant Change is inevitable, except from vending machines. On Monday, 17 July 2000 6:34, Waldo L. Jaquith [SMTP:waldo@munkandphyber.com] wrote: > "Waldo L. Jaquith" <waldo@munkandphyber.com> wrote:. > > I've got an array like this: > > $array[1][id] > > $array[1][rating] > > $array[2][id] > > $array[2][rating] > > $array[3][id] > > $array[3][rating] > > You'll note that it's now in order of 1, 3, 5, instead of 5, 1, 3. In SQL, > > this would be wicked easy. I could just do "ORDER BY rating". With > > two-dimensional arrays, of course, it's not so easy. I'm aware that I > > should > > be using usort, but I don't know how to go about applying it. I was hoping > > for something like "usort($array,rating,asc)", but Momma always called me a > > dreamer. :) > > > "O." <datahntr@yahoo.com> wrote: > > In SQL, you would probably store ID and RATING in two separate tables and > > JOIN them, or store them as fields in the same table. What you have here is > > not really an analogous setup. > > > > Why isn't the ID the index? Sorting on RATING would then be easier. If the > > IDs aren't sequential, use an associative array. Sorting would then be done > > using asort(). > > > > Also, to better mimic the SQL you know and love, you might use a construct > > like this instead of multidimensional arrays ... > > > > $array[index] = "string,string,string,string"; > > > > You can explode $array[index] into an array when you need it. Possibly CPU > > and time expensive, but probably easier to bend your mind around than > > multi-dimensional arrays. You can use a string as "index", and sort using > > the index (with ksort() )or the beginning of each element (with asort() ). > > Unfortunately, the setup, as you see it, is how it has to be. Given the > need for speed and the dynamic nature of these IDs and ratings (changing > frequently as a result of just-occurred user input), it's not practical to > spend time writing the data to a table and then extracting it again, only to > delete it. > > I will, however, try storing the strings as CSV and exploding them -- it's > just so crazy, it just might work. :) I'll also try Christopher Thompson's > <ct@arborinternet.com> fine sorting algorithm that he whipped up for me. > > Thanks, folks. > > Best, > Waldo > > > Waldo L. Jaquith > < waldo@munkandphyber.com > > < 804/979.2980 > > // Munk & Phyber > // 110B Second Street NE > // Charlottesville, VA 22902 >