php multidimensional array path segment combination loop - php

Question

I am trying to figure a way to get this to work. But I have a hard time thinking out the logics.
I have this array:
Array
(
[0] => Array
(
[0] => news
[1] => {section}
[2] => {slug}
[3] => {*}
)
[1] => Array
(
[0] => {id}
[1] => {*}
)
[2] => Array
(
[0] => {date}
[1] => 25-07-1982
[2] => {section}
[3] => {slug}
[4] => {*}
)
)
That I need to convert to this result:
0 news/{id}/{date}
1 news/{id}/25-07-1982
2 news/{id}/{section}
3 news/{id}/{slug}
4 news/{id}/{*}
5 news/{*}/{date}
6 news/{*}/25-07-1982
7 news/{*}/{section}
8 news/{*}/{slug}
9 news/{*}/{*}
10 {section}/{id}/{date}
11 {section}/{id}/25-07-1982
12 {section}/{id}/{section}
13 {section}/{id}/{slug}
14 {section}/{id}/{*}
15 {section}/{*}/{date}
16 {section}/{*}/25-07-1982
17 {section}/{*}/{section}
18 {section}/{*}/{slug}
19 {section}/{*}/{*}
20 {slug}/{id}/{date}
21 {slug}/{id}/25-07-1982
22 {slug}/{id}/{section}
23 {slug}/{id}/{slug}
24 {slug}/{id}/{*}
25 {slug}/{*}/{date}
26 {slug}/{*}/25-07-1982
27 {slug}/{*}/{section}
28 {slug}/{*}/{slug}
29 {slug}/{*}/{*}
30 {*}/{id}/{date}
31 {*}/{id}/25-07-1982
32 {*}/{id}/{section}
33 {*}/{id}/{slug}
34 {*}/{id}/{*}
35 {*}/{*}/{date}
36 {*}/{*}/25-07-1982
37 {*}/{*}/{section}
38 {*}/{*}/{slug}
39 {*}/{*}/{*}
The input array could contain more than three keys, so the solution I'm looking for should be dynamic. And the result should have the same order as the result shown above.
Does someone know how to do this in a efficient way? Can someone give me a push in the right direction? Thanks a lot! :)

Answer 1

Sth like this
foreach ($array[0] as $val0 )
foreach ($array[1] as $val1 )
foreach ($array[2] as $val2 )
$newArray[] = "$val0/$val1/$val2";
EDIT: for variable array length
function recursive($array , $length = 0){
$retval =array();
if($length < count($array) -1){
foreach ($array[$length] as $val0 )
foreach (recursive($array, $length+1) as $val1)
$retval[] = "$val0/$val1";
}
else
{
foreach ($array[$length] as $val0 )
$retval[] = "$val0";
}
return $retval;
}
print_r(recursive($array));

Answer 2

Just because I like writing functions that mis/manage PHP arrays, I put this together, mainly because I was pretty sure you could avoid recursion — because the structure itself isn't recursive. (My head seems to think that is a rule, I'm sure someone somewhere can prove it wrong).
foreach ( array_reverse($array) as $sub ) {
if ( isset($rem) ) {
$ret = array();
foreach ( $sub as $itm ) {
foreach ( $rem as $val ) { $ret[] = "$itm/$val"; }
}
$rem = $ret;
}
else {
$rem = $sub;
}
}
The output found in $rem is as follows:
Array (
[0] => news/{id}/{date}
[1] => news/{id}/25-07-1982
[2] => news/{id}/{section}
[3] => news/{id}/{slug}
[4] => news/{id}/{*}
[5] => news/{*}/{date}
[6] => news/{*}/25-07-1982
[7] => news/{*}/{section}
[8] => news/{*}/{slug}
[9] => news/{*}/{*}
[10] => {section}/{id}/{date}
[11] => {section}/{id}/25-07-1982
[12] => {section}/{id}/{section}
[13] => {section}/{id}/{slug}
[14] => {section}/{id}/{*}
[15] => {section}/{*}/{date}
[16] => {section}/{*}/25-07-1982
[17] => {section}/{*}/{section}
[18] => {section}/{*}/{slug}
[19] => {section}/{*}/{*}
[20] => {slug}/{id}/{date}
[21] => {slug}/{id}/25-07-1982
[22] => {slug}/{id}/{section}
[23] => {slug}/{id}/{slug}
[24] => {slug}/{id}/{*}
[25] => {slug}/{*}/{date}
[26] => {slug}/{*}/25-07-1982
[27] => {slug}/{*}/{section}
[28] => {slug}/{*}/{slug}
[29] => {slug}/{*}/{*}
[30] => {*}/{id}/{date}
[31] => {*}/{id}/25-07-1982
[32] => {*}/{id}/{section}
[33] => {*}/{id}/{slug}
[34] => {*}/{id}/{*}
[35] => {*}/{*}/{date}
[36] => {*}/{*}/25-07-1982
[37] => {*}/{*}/{section}
[38] => {*}/{*}/{slug}
[39] => {*}/{*}/{*}
)
Also, for those that like their arrays multidimensional, this might come in handy (although I'd hate to think what the overheads are for such a code golfed version). Just to be clear, this second example doesn't create the string list as requested by the OP, but a hierarchical array structure instead.
foreach ( array_reverse($array) as $sub ) {
$rem = isset($rem)
? array_combine($sub, array_fill(0, count($sub), $rem))
: $sub
;
}
This generates (again in $rem):
Array (
[news] => Array (
[{id}] => Array (
[0] => {date}
[1] => 25-07-1982
[2] => {section}
[3] => {slug}
[4] => {*}
)
[{*}] => Array (
[0] => {date}
[1] => 25-07-1982
[2] => {section}
[3] => {slug}
[4] => {*}
)
)
[{section}] => Array (
[{id}] => Array (
[0] => {date}
[1] => 25-07-1982
[2] => {section}
[3] => {slug}
[4] => {*}
)
... and so on
Now if only PHP had a join_recursive that included keys.
(it would be almost pointless, save for helping with the above).