Laravel access values from object in object - arrays

Question

In one of the controller function
$readings = Reading::orderBy('reading_date_time', 'DESC')->get();
dd($readings);
This gives
Illuminate\Database\Eloquent\Collection {#1883
#items: array:160 [
0 => App\Reading {#1722
#fillable: array:6 [ …6]
#connection: "mysql"
#table: "readings"
#primaryKey: "id"
#keyType: "int"
+incrementing: true
#with: []
#withCount: []
#perPage: 15
+exists: true
+wasRecentlyCreated: false
#attributes: array:8 [ …8]
#original: array:8 [ …8]
#changes: []
#casts: []
#dates: []
#dateFormat: null
#appends: []
#dispatchesEvents: []
#observables: []
#relations: []
#touches: []
+timestamps: true
#hidden: []
#visible: []
#guarded: array:1 [ …1]
}...
How can I access the actual values of readings table. And use them for operations like array_column().

Answer 1

This function already give you the result, and the result is collection.
You can call the attribute by single object in collection:
$readings->first()->reading_date_time;
and you can use method-pluck to get the attribute values from collection, it just like array_column:
$readings->pluck('reading_date_time');
If you use array_column, you can use method-toArray to change collection to array:
array_column($readings->toArray(), 'reading_date_time')

Answer 2

You may use toArray() helper
The toArray method converts the collection into a plain PHP array. If
the collection's values are Eloquent models, the models will also be
converted to arrays
$readings = Reading::orderBy('reading_date_time', 'DESC')->get()->toArray();
/*
[
['column1' => 'value1', 'column2' => 'value2', ...],
['column1' => 'value1', 'column2' => 'value2', ...],
['column1' => 'value1', 'column2' => 'value2', ...],
...
]
*/
Then you may use array_column() on $readings array
$pluckedValues = array_column($readings, 'chosen_column');
print_r($pluckedValues);