Re: problem with join(array, "")

> I've got the following code which splits an ip address into it's four > octets: > > $octet[4] = strtok($remote_ip, "."); > for ($i = 3; $i >= 1; $i--) { > $octet[$i] = strtok("."); > } > > If I add code as follows: > > for ($i = 1; $i <= 4; $i++) { > echo $octet[$1]; > } > > it prints the octects in reverse so 192.168.47.8 becomes 847168192. However, > if I add the following lines: > > $revip = join($octet, ""); > echo $revip; > > this should join the octet[] array into a string with "" as the separator. > However, when the output of the next line is not 847168192, it's 192168478. > > Anyone know if this is a bug or a feature? Am I misunderstanding something > here? I believe all that's happening is that the join() function walks through the array in the order of its elements without regard to the index used for accessing individual elements. So, I would guess the following would rectify your $revip problem... for ($i=1; $i <= 4; $i++) { $newarray[$i] = $octet[$i]; } $revip = join("", $newarray); echo $revip; ...but I'm not sure this is the best way in any case. what about the split() function, and so forth ... maybe just drop the "." characters from your original $remote_ip? Maybe something ugly but effective like ... list($a, $b, $c, $d) = split($remote_ip, ".", 4); $revip = $d . $c . $b . $a; Or... $revip = ""; $octet[4] = strtok($remote_ip, "."); for ($i = 1; $i <= 4; $i++) { // Or use a while, in case partial address. $revip .= strtok("."); } Hope this helps, James.