Array create group on the basis of particular field value

Question

I have the following array

array
(
    [0] => Array
    (
        [market_id] => 10
        [competition_id] => 31        
    )

    [1] => Array
    (
        [market_id] => 10
        [competition_id] => 31        
    )

    [2] => Array
    (
        [market_id] => 11
        [competition_id] => 31        
    )

    [3] => Array
    (
        [market_id] => 11
        [competition_id] => 31        
    )

    [4] => Array
    (
        [market_id] => 11
        [competition_id] => 31        
    )
)

Is there a single function to create below array from the above input or do I have to traverse array manually and get the desired result?

array
(
    [0] => Array
    (
        [0] => Array
        (
            [market_id] => 10
            [competition_id] => 31        
        )
        [1] => Array
        (
            [market_id] => 10
            [competition_id] => 31        
        )
    )
    [1] => Array
    (
        [0] => Array
        (
            [market_id] => 11
            [competition_id] => 31        
        )
        [1] => Array
        (
            [market_id] => 11
            [competition_id] => 31        
        )
        [2] => Array
        (
            [market_id] => 11
            [competition_id] => 31        
        )        
    )
)

All I want is to group my array elements on the basis of market_id field.

How you are getting input array, if you are getting from db then you can use group by clause. — khanz, Feb 11 '15 at 07:18
single function? none, i don't think so, just manually create another one, a simple foreach and `array_values` to reindex is enough. — Kevin, Feb 11 '15 at 07:28
http://stackoverflow.com/questions/7574857/group-array-by-subarray-values - same question — Sergei Gorjunov, Feb 11 '15 at 07:32

score 2 · Answer 1 · answered Feb 11 '15 at 08:51

Additionaly when you don't want to do his in vanilla PHP, you can use ouzo-goodies:

$array = array(
    0 => array(
        'market_id' => '10',
        'competition_id' => '31'
    ),
    1 => array(
        'market_id' => '10',
        'competition_id' => '31'
    ),
    2 => array(
        'market_id' => '11',
        'competition_id' => '31'
    ),
    3 => array(
        'market_id' => '11',
        'competition_id' => '31'
    ),
    4 => array(
        'market_id' => '11',
        'competition_id' => '31'
    )
);

$groupBy = Arrays::groupBy($array, Functions::extract()->market_id);

print_r($groupBy);

And result:

Array
(
    [10] => Array
        (
            [0] => Array
                (
                    [market_id] => 10
                    [competition_id] => 31
                )

            [1] => Array
                (
                    [market_id] => 10
                    [competition_id] => 31
                )

        )

    [11] => Array
        (
            [0] => Array
                (
                    [market_id] => 11
                    [competition_id] => 31
                )

            [1] => Array
                (
                    [market_id] => 11
                    [competition_id] => 31
                )

            [2] => Array
                (
                    [market_id] => 11
                    [competition_id] => 31
                )

        )

)

Here is docs for Arrays and Functions.

i get an error Class 'Arrays' not found in /var/www/test/group.php on line 31 — Neeraj, Feb 11 '15 at 09:41

score 1 · Accepted Answer · answered Feb 11 '15 at 08:57

1

No shortcuts. Construct a new array with market_id as the keys, then remove the interim keys:

$result = [];
foreach ($array as $item) {
    $result[$item['market_id']][] = $item;
}
$result = array_values($result);

answered Feb 11 '15 at 08:57

Ja͢ck

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Array create group on the basis of particular field value

2 Answers2