Laravel collection converts array to object

问题

If I run $collection->filter(myFilter), Laravel does this annoying thing of adding keys to each model in the collection like so:

{
    "4": {
        "myObject": "data"
    },
    "7": {
        "myObject": "data"
    }
}

How can I get rid of the "4" and "7" so it's an array of my objects?

My code that runs is:

$obj = Cars::with('brand')->orderBy('id')->get();

return $obj->filter(function($value, $key)
{
    return $value->display == true;
});

回答1:

The issue is that the filter() method does not rekey the underlying collection array. So, the Collection is still representing an array, it is just that your array looks like this:

[
    4 => Object4,
    7 => Object7,
]

While this is a perfectly valid array in PHP, this is not a proper array in JSON. Since this cannot be represented as an array in JSON, it is converted to an object in JSON.

In order to get this properly represented as an array in JSON, you just need to rekey the Collection array. The proper method for this is the values() method. All it does is call array_values on the underlying array. This will turn the above array in this:

[
    0 => Object4,
    1 => Object7,
]

Now, this is a proper numerically indexed array that JSON can understand and will treat as an array instead of an object.

While flatten may work for this particular case (your Collection is a collection of Eloquent Models), it is not actually the correct method, and may lead to unintended consequences. Additionally, it will perform a lot of extra logic that is not needed. Your best bet is to use the proper method for what you are trying to achieve, and that is the values() method.

$obj = Cars::with('brand')->orderBy('id')->get();

return $obj->filter(function($value, $key)
    {
        return $value->display == true;
    })
    ->values();

回答2:

Calling flatten() on your collection should remove the keys and merge all their values up into a single collection.

来源：https://stackoverflow.com/questions/42182919/laravel-collection-converts-array-to-object

标签

php

json

laravel

laravel-collection