CODEWITHSUNDEEP
phplaravelflattencollect
GTMeteor
GTMeteor

Reputation: 857

PHP Laravel 5.5 collections flatten and keep the integer keys?

I have the following array :

$array = [
    '2' => ['3' => ['56' => '2'], '6' => ['48' => '2']],
    '4' => ['4' => ['433' => '2', '140' => '2'], '8' => ['421' => '2', '140' => '2']],
    '5' => ['5' => ['88' => '4', '87' => '2']]
];

The following code (flattening) should return it by preserving keys, but it doesnt?

collect($array)->flatten(1);

should give me 

[
    '3' => ['56' => '2'],
    '6' => ['48' => '2'],
    '4' => ['433' => '2', '140' => '2'],
    '8' => ['421' => '2', '140' => '2'],
    '5' => ['88' => '4', '87' => '2']
]

However it loses the keys, and just gives array results :/ Am I using it wrong? How should I flatten and preserve keys?

Upvotes: 13

Views: 21542

Answers (3)

mickmackusa
mickmackusa

Reputation: 48041

mapWithKeys() is most direct if you wish to return a collection of all second level data as the new first level.

If you wish to return an array, you can call reduce() and use the array union operator in the callback. Otherwise, call toArray() after mapWithKeys() to produce an array.

Codes: (Demo)

var_export(
    collect($array)->reduce(fn($result, $set) => $result + $set, [])
);

Is the same as:

var_export(
    collect($array)->mapWithKeys(fn($set) => $set)->toArray()
);

Upvotes: 0

bmagg
bmagg

Reputation: 946

An elegant solution is to use the mapWithKeys method. This will flatten your array and keep the keys:

collect($array)->mapWithKeys(function($a) {
    return $a;
});

The mapWithKeys method iterates through the collection and passes each value to the given callback. The callback should return an associative array containing a single key / value pair

Upvotes: 56

Alexey Mezenin
Alexey Mezenin

Reputation: 163948

You can't use flatten() here. I don't have an elegant solution, but I've tested this and it works perfectly for your array:

foreach ($array as $items) {
    foreach ($items as $key => $item) {
        $newArray[$key] = $item;
    }
}

dd($newArray);

Upvotes: 2

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