PHP- Array combine not working properly - php

Question

I am trying to do array combine, but it is not working properly. I have one array called $models which consits of objects and it looks like this:
array:5 [▼
0 => Comment {#377 ▶}
1 => Thumb {#378 ▶}
2 => View {#379 ▶}
3 => Vote {#380 ▶}
]
Then since I am passing it to another function, I am adding one more object as an element like this:
array_push($models, new User);
And then I get an array that looks like this:
array:5 [▼
0 => Comment {#377 ▶}
1 => Thumb {#378 ▶}
2 => View {#379 ▶}
3 => Vote {#380 ▶}
4 => User {#399 ▶}
]
I am then doing foreach loop to get the total count in the DB for each model like this:
foreach ($models as $model){
$modelCounts[] = $model->count();
}
My $modelCounts than looks like this:
array:5 [▼
0 => 19
1 => 22
2 => 15
3 => 17
4 => 3
]
And then I am trying to do array_combine so that my objects are keys and the counts are values like this:
$result = array_combine($models, $modelCounts);
But something is not working right because when I do dd($result); I get:
array:1 [▼
"[]" => 3
]
But when I do it the other way around like this:
$result = array_combine($modelCounts, $models);
It works fine and I get:
array:5 [▼
19 => Comment {#377 ▶}
22 => Thumb {#378 ▶}
15 => View {#379 ▶}
17 => Vote {#380 ▶}
3 => User {#399 ▶}
]
But I need it the other way around and not like this.

Answer 1

Objects can't be used as key for associative arrays, only scalar values are allowed.
http://php.net/manual/en/language.types.array.php
Arrays and objects can not be used as keys. Doing so will result in a warning: Illegal offset type.

Answer 2

The reason why the first array_combine() fails is that an objcect cannot be usead as an array key.
You may want to create an array containing classes names first by using get_class() to get class's name and then combine it with $modelCounts
It should look something like this
foreach ($models as $model){
$modelNames[] = get_class($model);
}
$result = array_combine($modelNames, $modelCounts);