php split array into smaller even arrays

问题

I have a function that is supposed to split my array into smaller, evenly distributed arrays, however it seems to be duplicating my data along the way. If anyone can help me out that'd be great.

Here's the original array:

Array
(
    [0] => stdClass Object
        (
            [bid] => 42
            [name] => Ray White Mordialloc
            [imageurl] => sp_raywhite.gif
            [clickurl] => http://www.raywhite.com/
        )

    [1] => stdClass Object
        (
            [bid] => 48
            [name] => Beachside Osteo
            [imageurl] => sp_beachside.gif
            [clickurl] => http://www.beachsideosteo.com.au/
        )

    [2] => stdClass Object
        (
            [bid] => 53
            [name] => Carmotive
            [imageurl] => sp_carmotive.jpg
            [clickurl] => http://www.carmotive.com.au/
        )

    [3] => stdClass Object
        (
            [bid] => 51
            [name] => Richmond and Bennison
            [imageurl] => sp_richmond.jpg
            [clickurl] => http://www.richbenn.com.au/
        )

    [4] => stdClass Object
        (
            [bid] => 50
            [name] => Letec
            [imageurl] => sp_letec.jpg
            [clickurl] => www.letec.biz
        )

    [5] => stdClass Object
        (
            [bid] => 39
            [name] => Main Street Mordialloc
            [imageurl] => main street cafe.jpg
            [clickurl] => 
        )

    [6] => stdClass Object
        (
            [bid] => 40
            [name] => Ripponlea Mitsubishi
            [imageurl] => sp_mitsubishi.gif
            [clickurl] => 
        )

    [7] => stdClass Object
        (
            [bid] => 34
            [name] => Adrianos Pizza & Pasta
            [imageurl] => sp_adrian.gif
            [clickurl] => 
        )

    [8] => stdClass Object
        (
            [bid] => 59
            [name] => Pure Sport
            [imageurl] => sp_psport.jpg
            [clickurl] => http://www.puresport.com.au/
        )

    [9] => stdClass Object
        (
            [bid] => 33
            [name] => Two Brothers
            [imageurl] => sp_2brothers.gif
            [clickurl] => http://www.2brothers.com.au/
        )

    [10] => stdClass Object
        (
            [bid] => 52
            [name] => Mordialloc Travel and Cruise
            [imageurl] => sp_morditravel.jpg
            [clickurl] => http://www.yellowpages.com.au/vic/mordialloc/mordialloc-travel-cruise-13492525-listing.html
        )

    [11] => stdClass Object
        (
            [bid] => 57
            [name] => Southern Suburbs Physiotherapy Centre
            [imageurl] => sp_sspc.jpg
            [clickurl] => http://www.sspc.com.au
        )

    [12] => stdClass Object
        (
            [bid] => 54
            [name] => PPM Builders
            [imageurl] => sp_ppm.jpg
            [clickurl] => http://www.hotfrog.com.au/Companies/P-P-M-Builders
        )

    [13] => stdClass Object
        (
            [bid] => 36
            [name] => Big River
            [imageurl] => sp_bigriver.gif
            [clickurl] => 
        )

    [14] => stdClass Object
        (
            [bid] => 35
            [name] => Bendigo Bank Parkdale / Mentone East
            [imageurl] => sp_bendigo.gif
            [clickurl] => http://www.bendigobank.com.au
        )

    [15] => stdClass Object
        (
            [bid] => 56
            [name] => Logical Services
            [imageurl] => sp_logical.jpg
            [clickurl] => 
        )

    [16] => stdClass Object
        (
            [bid] => 58
            [name] => Dicount Lollie Shop
            [imageurl] => new dls logo.jpg
            [clickurl] => 
        )

    [17] => stdClass Object
        (
            [bid] => 46
            [name] => Patterson Securities
            [imageurl] => cmyk patersons_withtag.jpg
            [clickurl] => 
        )

    [18] => stdClass Object
        (
            [bid] => 44
            [name] => Mordialloc Personal Trainers
            [imageurl] => sp_mordipt.gif
            [clickurl] => #
        )

    [19] => stdClass Object
        (
            [bid] => 37
            [name] => Mordialloc Cellar Door
            [imageurl] => sp_cellardoor.gif
            [clickurl] => 
        )

    [20] => stdClass Object
        (
            [bid] => 41
            [name] => Print House Graphics
            [imageurl] => sp_printhouse.gif
            [clickurl] => 
        )

    [21] => stdClass Object
        (
            [bid] => 55
            [name] => 360South
            [imageurl] => sp_360.jpg
            [clickurl] => 
        )

    [22] => stdClass Object
        (
            [bid] => 43
            [name] => Systema
            [imageurl] => sp_systema.gif
            [clickurl] => 
        )

    [23] => stdClass Object
        (
            [bid] => 38
            [name] => Lowe Financial Group
            [imageurl] => sp_lowe.gif
            [clickurl] => http://lowefinancial.com/
        )

    [24] => stdClass Object
        (
            [bid] => 49
            [name] => Kim Reed Conveyancing
            [imageurl] => sp_kimreed.jpg
            [clickurl] => 
        )

    [25] => stdClass Object
        (
            [bid] => 45
            [name] => Mordialloc Sporting Club
            [imageurl] => msc logo.jpg
            [clickurl] => 
        )

)

Here's the php function which is meant to split the array:

function split_array($array, $slices) { 

        $perGroup = floor(count($array) / $slices);
        $Remainder = count($array) % $slices ;
        $slicesArray = array();

        $i = 0;
        while( $i < $slices ) {
            $slicesArray[$i] = array_slice($array, $i * $perGroup, $perGroup);
            $i++;
        }

        if ( $i == $slices ) { 
            if ($Remainder > 0 && $Remainder < $slices) {

                $z = $i * $perGroup +1;
                $x = 0;
                while ($x < $Remainder) {

                    $slicesRemainderArray = array_slice($array, $z, $Remainder+$x);
                    $remainderItems = array_merge($slicesArray[$x],$slicesRemainderArray);
                    $slicesArray[$x] = $remainderItems;

                $x++;
                $z++;
                }
            }
        };

        return $slicesArray;
    }

Here's the result of the split (it somehow duplicates items from the original array into the smaller arrays):

^^ As you can see there are duplicates from the original array in the newly created smaller arrays.

I thought I could remove the duplicates using a multi-dimensional remove duplicate function but that didn't work. I'm guessing my problem is in the array_split function.

Any suggestions? :)

回答1:

EDIT: There's array_chunk, which does just that.

Well, I didn't feel like debugging, so I wrote a version with array_reduce:

$pergroup = 2;
$redfunc = function ($partial, $elem) use ($pergroup) {
    $groupCount = count($partial);
    if ($groupCount == 0 || count(end($partial)) == $pergroup)
        $partial[] = array($elem);
    else
        $partial[$groupCount-1][] = $elem;

    return $partial;
};

$arr = array(1,2,3,4,5);

print_r(array_reduce($arr, $redfunc, array()));

gives

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

    [1] => Array
        (
            [0] => 3
            [1] => 4
        )

    [2] => Array
        (
            [0] => 5
        )

)

回答2:

$sections = array_chunk(array('k', 'l', 'm', 'n', 'o'), 2);

回答3:

It seems to me that the distribution of the remaining items is too complicated.

If you know how many items are missing ($Remainder), why don´t you just generate a remaining slice and pop-off items with array_pop() until it´s empty?

By the way, you can use that procedure for the whole array as well.

回答4:

function split_array(&$array, $slices) {
  $result = array();
  $l = count($array)-1;
  for ($i=0; $i<=$l; $i++) {
    if ($i == 0  || $i % $slices == 0) $tmp = array();
    $tmp[] = $array[$i];
    if ($i == $l || $i % $slices == 1) $result[] = $tmp; 
  }
  return $result;
}

回答5:

There's array_chunk, which does just that.

http://www.php.net/manual/en/function.array-chunk.php

[just making the salient part of Artefacto's answer more explicit]

回答6:

array_chunk doesn't fill the arrays evenly unless the total number of elements is divisible by the number of chunks you want; the last chunk may be much smaller than the first (e.g. if you have seven elements and you split in to three chunks, you'll get arrays containing three, three and one element).

The following implementation will attempt to smooth this out so that the array sizes are more even if that's what you're after, e.g. if you have seven elements you'll get chunks arrays containing three, two and two elements instead. It's still not even, but it's more even. It falls back to using array_chunk if the count is evenly divisible by the number of columns, as that will be faster (especially if you have large arrays).

<?php
function array_group($array, $num)                                                
{                                                                           
    $num = (int) $num;                                                      
    if ($num < 1) {                                                         
        throw new \InvalidArgumentException('At least one group must be returned.');
    }                                                                       

    $count = count($array);                                                
    if ($count && $count % $num === 0) {                                    
        return array_chunk($array, $count / $num);                         
    }                                                                       

    $groups = [];                                                           
    $offset = 0;                                                            
    do {                                                                    
        $length   = ceil(($count - $offset) / $num);                
        $groups[] = array_slice($array, $offset, $length);                 
        $offset   += $length;                                               
    } while (--$num);                                                       

    return $groups;                                                         
} 

print_r(array_chunk(array(1, 2, 3, 4, 5, 6, 7), 3));
/* Produces
Array
(
    [0] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
        )

    [1] => Array
        (
            [0] => 4
            [1] => 5
            [2] => 6
        )

    [2] => Array
        (
            [0] => 7
        )

) */

print_r(array_group(array(1, 2, 3, 4, 5, 6, 7), 3));
/* Produces
Array
(
    [0] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
        )

    [1] => Array
        (
            [0] => 4
            [1] => 5
        )

    [2] => Array
        (
            [0] => 6
            [1] => 7
        )
) */

回答7:

Try this a simple usage. When it finds empty string it splits the array into two arrays. One from beggining to empty string index. Other from empty string index to the last.
Note : Emty string is not included in both. it is used only for condition checking.

    $column[] = "id";
    $column[] = "name";
    $column[] = "email";
    $column[] = "password";
    $column[] = "";
    $column[] = "uid";
    $column[] = "uname";
    $column[] = "mname";
    $column[] = "lname";
    $column[] = "city";
    $column[] = "country";
    $column[] = "zip";
    $column[] = "cell";
    $column[] = "address";
    split_array($column);

function split_array($column)
{

    $total = count($column);
    $num = array_search('',$column);

    $split = $total - $num ;
    $outer_sql = array_slice( $column , - ($split) + 1);
    array_splice($column , $num);

    echo "<pre>";
    print_r($outer_sql);
    echo "</pre>";
    echo "<pre>";
    print_r($column);
    echo "</pre>";  

}

回答8:

It is simple way to divide php array in two equal sections. and you can fetch all elements and values of both arrays using foreach easity

list($firstarray, $secondarray) = array_chunk($vorstand_two_column, ceil(count($all_array_contents) / 2));  

foreach($firstarray as $fa) {
.... Code ....
}

foreach($secondarray as $sa) {
.... Code ....
}

来源：https://stackoverflow.com/questions/2861530/php-split-array-into-smaller-even-arrays

标签

php

arrays

split

evenly