Array issues kill death

Grim... · **Posted:** Tue Aug 04, 2009 19:05

I can't seem to get my head around the logic of this.

Say you have a multi-array:

Code:

Array
(
    [0] => Array
        (
            [0] => $value
            [1] => $value
        )

    [1] => Array
        (
            [0] => $value
            [1] => $value
            [2] => $value
            [3] => $value
        )

    [2] => Array
        (
            [0] => $value
            [1] => $value
        )
)

That array can have any number of values in the first array, and any number in the second, but it will only ever be two deep.

So, using the one above as an example, I want to step through it 'sideways' to get every possible combination of values, so

Code:

array[0][0]
array[1][0]
array[2][0]

array[0][0]
array[1][0]
array[2][1]

array[0][0]
array[1][1]
array[2][0]

array[0][0]
array[1][1]
array[2][1]

array[0][0]
array[1][2]
array[2][0]

array[0][0]
array[1][2]
array[2][1]

array[0][0]
array[1][3]
array[2][0]

array[0][0]
array[1][3]
array[2][1]

array[0][1]
array[1][0]
array[2][0]

array[0][1]
array[1][0]
array[2][1]

array[0][1]
array[1][1]
array[2][0]

array[0][1]
array[1][2]
array[2][0]
...

Etc.
There must be a way of doing it with loops and I've been trying for two hours and I can't and it's driving me fucking mad.
FIX!

SkyKid · **Joined:** 30th Mar, 2008 **Posts:** 98

We're talking PHP presumably?

You'll have to iterate through them yourself, either by:
1) taking array_keys() and building a list (in another array) of where you're up to.
or
2) dicking about with the internal array pointers with functions like 'reset', 'current' and 'next'

The latter's probably faster, but the former might be more sane to code.

EDIT: Wait, perhaps I misunderstand...

Grim... · **Posted:** Tue Aug 04, 2009 19:21

There might be an easier way than that - I think I'm getting too caught up in the order they come back in when it doesn't really matter, just as long as they all come back.
So three embedded loops should do it.

IFeelAsleep · **Joined:** 15th May, 2009 **Posts:** 368

That doesn't quite make sense to me I think they are 1-dimensional arrays though, and you have an array of arrays. Take a mental step back. Your outer loop will be the number of arrays you want to loop through. The next loop will be the number of records in each array. What are you working in?

Edit I see someone has replied. I shall post this anyway

The Rev Owen · **Posted:** Tue Aug 04, 2009 19:25

foreach?

Grim... · **Posted:** Tue Aug 04, 2009 19:31

IFeelAsleep wrote:

Take a mental step back. Your outer loop will be the number of arrays you want to loop through. The next loop will be the number of records in each array. What are you working in?

Whatever you can demonstrate in is fine - it's a logic problem rather than a coding one.

End of an Era · **Joined:** 25th Nov, 2008 **Posts:** 1041

for ( int i = 0; i < outerArray.Length; i++ )
{

for ( int j = 0; j < outerArray[i].Length; j++ )
{

doSomethingWith(outerArray[i][j]);

}

}

Wouldn't that do it?

IFeelAsleep · **Joined:** 15th May, 2009 **Posts:** 368

Right oh. Give me a mo, I am just firing up visual studio. So that will be about half an hour, plus the time it takes me to work something out.

Edit: err, yeah, what End of an Era said.

SkyKid · **Joined:** 30th Mar, 2008 **Posts:** 98

No attempt made to make it pretty... this should spit out in the original order you asked for. What do I win?

Code:

<?php

$parseJunk = Array
(
    '0' => Array
        (
            '0' => '0-0',
            '1' => '0-1',
        ),

    '1' => Array
        (
            '0' => '1-0',
            '1' => '1-1',
            '2' => '1-2',
            '3' => '1-3',
        ),

    '2' => Array
        (
            '0' => '2-0',
            '1' => '2-1',
        ),
);


// Build first 'currentKey' and 'topLevelKeyCount' as the limiter
$topLevelKeyCount = array();
$currentKey = array();
foreach( array_keys( $parseJunk ) as $topLevelKey ) {
   $topLevelKeyCount[] = count( $parseJunk[ $topLevelKey ] );
   $currentKey[] = 0;
}
$subKeyCount = count( $topLevelKeyCount );



do {
   echo 'Grouping: ';
   for( $subKeyIndex = 0; $subKeyIndex < $subKeyCount; ++$subKeyIndex ) {
      echo $parseJunk[ $subKeyIndex ][ $currentKey[ $subKeyIndex ] ].' ';
   }
   echo '<br />';
} while( $currentKey = nextKeyGet( $topLevelKeyCount, $currentKey ) );




// returns false if finished, or next 'key'
function nextKeyGet( $pKeyCount, $pCurrentKey ) {
   $subkeyIndex = count( $pCurrentKey ) - 1;

   while( $subkeyIndex >= 0 ) {
      if( $pCurrentKey[ $subkeyIndex ] + 1 < $pKeyCount[ $subkeyIndex ] ) {
         $pCurrentKey[ $subkeyIndex ] ++;
         return $pCurrentKey;
      }

      $pCurrentKey[ $subkeyIndex ] = 0;
      $subkeyIndex --;
   }

   return false;
}


?>

IFeelAsleep · **Joined:** 15th May, 2009 **Posts:** 368

Show off!

Grim... · **Posted:** Tue Aug 04, 2009 20:03

Jesus, I thought it'd be simpler than that. Thanks man, I'll take a look tomorrow. I not going to think about this any more tonight.

Grim... · **Posted:** Wed Aug 05, 2009 9:40

SkyKid wrote:

What do I win?

Not much, it just outputs the same thing 16 times

MaliA · **Posted:** Wed Aug 05, 2009 9:41

Grim... wrote:

SkyKid wrote:

What do I win?

Not much, it just outputs the same thing 16 times

Like myp when he posts links, then.

Pod · **Joined:** 30th Mar, 2008 **Posts:** 2568

I don't know PHP, nor do I care to, but in other languages it's just:

Code:

    for length of array
        for length of sub-array

(edit: a quick google says it's "count()")

edit: I don't do PHP, but adapting the above answer and guessing:

Code:

for (i = 0; i < conut(array); i++ )
{
    for ( int j = 0; j < count(array[i]); j++ )
    {
        doSomethingWith(array[i][j]);
    }
}

also: Why not try asking these sorts fo things on Stackoverflow ?

Grim... · **Posted:** Wed Aug 05, 2009 10:19

No it's not.
I need every combination of x arrays.

Pod · **Joined:** 30th Mar, 2008 **Posts:** 2568

That is?

Array[2][2]:

0,0
0,1
1,0
1,1

isn't that every combination?

Grim... · **Posted:** Wed Aug 05, 2009 10:27

I have simplified the first post

Is anyone a member of expert sexchange?

http://www.experts-exchange.com/Web_Dev ... 80571.html

Pod · **Joined:** 30th Mar, 2008 **Posts:** 2568

experts exchange is shit. Use stackoverflow instead.

(also: it would help if your array exampel didn't go up to [1][4] [1][3]

)

TBH: I don't understand what you're trying to do. If you take your orignial output and do this:

H:\>cat pooooo.txt | sort | uniq
array[0][0]
array[0][1]
array[1][0]
array[1][1]
array[1][2]
array[1][3]
array[1][4]
array[2][0]
array[2][1]

notice how that's exactly the same as a normal loopover? What exactly are you trying to do?

Grim... · **Posted:** Wed Aug 05, 2009 10:32

This:

Code:

        function findcombination($a){
           $out = array();
           if (count($a) == 1) {
              $x = array_shift($a);
              foreach ($x as $v) $out[] = array($v);
              return $out;
           }
           foreach ($a as $k=>$v){
              $b = $a;
              unset($b[$k]);
              $x = findcombination($b);
              foreach ($v as $v1){
                 foreach ($x As $v2) 
                 $out[] = array_merge(array($v1), $v2);
              }
           }
           return $out;
        }

Thanks all!

Grim... · **Posted:** Wed Aug 05, 2009 10:33

Pod wrote:

(also: it would help if your array exampel didn't go up to [1][4] [1][3]

)

Oh yeah, oops

SkyKid · **Joined:** 30th Mar, 2008 **Posts:** 98

I did test the original code - it was working for me

Here's an alternative, if you don't care about order. Looks like you've got a recursive one already tho...

Code:

parseLevel( $parseJunk, 0, array() );

function parseLevel( $pJunkArray, $pLevel, $pKeyList ) {
// terminate...
   if( $pLevel == count( $pJunkArray ) ) {
      echo 'group: ';
      for( $iKeyIndex = 0; $iKeyIndex < $pLevel; $iKeyIndex ++ ) {
         echo "[{$iKeyIndex}-{$pKeyList[$iKeyIndex]} = {$pJunkArray[ $iKeyIndex ][ $pKeyList[$iKeyIndex] ]}] ";
      }
      echo '<br />';
      return;
   }

// recurse...
   $nextLevel = $pLevel + 1;
   foreach( array_keys( $pJunkArray[ $pLevel ] ) as $pKey ) {
      $newKeyList = $pKeyList;
      $newKeyList[] = $pKey;
      parseLevel( $pJunkArray, $nextLevel, $newKeyList );
   }
}

Now... back to my own work

Joans · **Joined:** 31st Mar, 2008 **Posts:** 8655

Grim... wrote:

I have simplified the first post

Is anyone a member of expert sexchange?

http://www.experts-exchange.com/Web_Dev ... 80571.html

Scroll all the way to the bottom of the page to see the answers on experts exchange (although this doesn't work on the mobile site, which can be a bit annoying).

Cras · **Joined:** 30th Mar, 2008 **Posts:** 49244

I thought that, then I clicked on Grim...'s link, and they weren't there.

And now they're there again. Odd.

Doctor Glyndwr · **Joined:** 30th Mar, 2008 **Posts:** 32624

That only seems to work sometimes on that crappy site. The google cache is the best way, for example:

http://209.85.229.132/search?q=cache:nP ... =firefox-a

Edit -- it's something to do with the SEO, of course.

Joans · **Joined:** 31st Mar, 2008 **Posts:** 8655

Oh sorry, I think they've always been there when I've looked and I must admit I didn't actually click on Grim...'s link.

Be Excellent To Each Other

Array issues kill death
Fuck's sake

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Be Excellent To Each Other

Array issues kill death Fuck's sake

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Array issues kill death
Fuck's sake