[9.x] Add keyBy() method to Arr helpers

[medeirosinacio]

Hi guys, this is my first PR. Please let me know if you have anything to change or improve. This method was inspired by the ArrayHelper::index of the Yii2 framework. I used this method a lot to format arrays and I would really like laravel to have it too

Indexes the array according to a specified key.

use case

$array = [
    ['id' => '123', 'data' => 'abc', 'device' => 'laptop'],
    ['id' => '345', 'data' => 'def', 'device' => 'tablet'],
    ['id' => '345', 'data' => 'hgi', 'device' => 'smartphone'],
];
$result = Arr::index($array, 'id');

The result will be an associative array, where the key is the value of id attribute

[
    '123' => ['id' => '123', 'data' => 'abc', 'device' => 'laptop'],
    '345' => ['id' => '345', 'data' => 'hgi', 'device' => 'smartphone']
    // The second element of an original array is overwritten by the last element because of the same id
]

• Renamed Arr:index to Arr:keyBy

[pyrou]

About naming, same behavior exists on Collection, its named keyBy

[medeirosinacio]

About naming, same behavior exists on Collection, its named keyBy

Yes true! I can change the name of the method to leave both with the same behavior. It would be interesting for the Arr class to also have this method.

[dennisprudlo]

If this array helper and the collection function are supposed to do the same we maybe should simply use

collect($array)->keyBy('id')

or if merged update the keyBy function of the collection to use the Arr::index() helper. Otherwise we'd end up with two different versions of this kind of function.

[taylorotwell]

If we already have a collection method that does the exact same thing then this method should be named the same as well.

[medeirosinacio]

If we already have a collection method that does the exact same thing then this method should be named the same as well.

Hello, I refactored the method to use the function that already exists in the collection.

Let Me know if anything is missing.

[medeirosinacio]

If this array helper and the collection function are supposed to do the same we maybe should simply use

collect($array)->keyBy('id')

or if merged update the keyBy function of the collection to use the Arr::index() helper. Otherwise we'd end up with two different versions of this kind of function.

Yes, I made the change so that the method uses the existing function in the collection