CODEWITHSUNDEEP
phparrays
Testy
Testy

Reputation: 301

From an array, group items based on the key value with PHP

I've this multidimensional array in PHP:

Array
(
    [0] => Array
        (
            [continent] => Europa
            [country] => France
            [capital] => Paris
        )

    [1] => Array
        (
            [continent] => Europa
            [country] => Spain
            [capital] => Madrid
        )
    [2] => Array
        (
            [continent] => Asia
            [country] => Russia
            [capital] => Moscow
        )
)

How can I group countries depending the continent ?

So countries in the same continent should be group together.

The desired output should be:

Array
(
    [Europa] => Array
        (
            [country] => France
            [capital] => Paris
        ),
        (
            [country] => Spain
            [capital] => Madrid
        )
    [Asia] => Array
        (
            [country] => Russia
            [capital] => Moscow
        )
)

How it is possible with PHP please ?

Thanks.

Upvotes: 1

Views: 225

Answers (3)

Jared Farrish
Jared Farrish

Reputation: 49208

$groupByContinent = function(array $list) {
    return array_reduce($list, function($grouped, $item) {
        $grouped[$item['continent']][] = $item;
        return $grouped;
    }, []);
};

$groupedByContinent = $groupByContinent($data);

https://3v4l.org/s6X1c

Or:

$groupByProperty = function(array $list, string $property) {
    return array_reduce($list, function($grouped, $item) use(&$property) {
        $grouped[$item[$property]][] = $item;
        return $grouped;
    }, []);
};

$groupedByContinent = $groupByProperty($data, 'continent');

https://3v4l.org/Be3HL

Upvotes: 1

Naveed
Naveed

Reputation: 42093

You can also try:

$data = array(
    array(  
        "continent" => "Europa",
        "country" => "France",
        "capital" => "Paris",
        ),
   array(
       "continent" => "Europa",
       "country" => "Spain",
       "capital" => "Madrid",
       ),
   array(
       "continent" => "Asia",
       "country" => "Russia",
       "capital" => "Moscow",
       )
);


$group_by = 'continent';
$attributes = array( 'country', 'capital' );

$output = array();
foreach( $data as $country ) {

    if( isset( $country[$group_by] ) ) {

        $one = array();
        foreach( $attributes as $attribute ) {
            if( isset( $country[$attribute] ) ) {
                $one[$attribute] = $country[$attribute];
            }
        }
        $output[ $country[$group_by] ][] = $one;
     }
}


print_r($output);

Demo

Upvotes: 0

Omari Celestine
Omari Celestine

Reputation: 1435

You can create a new array variable, loop through your data array checking to see if the key has already been created and if not, create it and add the related data to that key.

<?php
// $data: the name of your array
$grouped_data = array();

for ($i = 0; $i < count($data); $i++) {
    $key = $data[$i]['continent'];

    if (!isset($grouped_data[$key])) {
        $grouped_data[$key] = array();
    }

    $grouped_data[$key][] = array(
        'country' => $data[$i]['country'],
        'capital' => $data[$i]['capital']
    );
}
?>

Upvotes: 1

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