Modify/add/rename eloquent collection - laravel

Question

Let's say I've got eloquent collection returns from:
$b = Book::get(); (columns: id, book_name, pages)
$m = Magazine::get(); (columns, id, mag_name, type)
How do I then:
Combine them in the same collection.
Rename ->book_name/mag_name to k
Add type and if book use 'null' as value
add ->hash (str::random)
I want to keep the collection to be able to use the benifits that come with it. ie. not convert it to an array.
Laravel 7

Answer 1

You can do it with collection merge method
$b = Book::get(['id','book_name as k','pages']);
$m = Magazine::get(['id','mag_name as k','type']);
$bb = $b->map(function ($book){
$book['type'] = null;
$book['hash'] = Str::random();
return $book;
});
$mm = $m->map(function ($magzine){
$magzine['hash'] = Str::random();
return $magzine;
});
$merged = $bb->merge($mm);
return $merged;

Answer 2

Assume we have the following collections:
$b = Book::get(); //(columns: id, book_name, pages)
$m = Magazine::get(); //(columns, id, mag_name, type)
Second, update the fields:
$books = $b->map(function ($book) => {
return [
'id' => $book->id,
'k' => $book->book_name,
'type' => null,
'hash' => Str::random()
];
});
$magazines = $b->map(function ($magazine) => {
return [
'id' => $magazine->id,
'k' => $magazine->mag_name,
'type' => $magazine->type,
'hash' => Str::random()
];
});
Third, merge the collections:
$result = $books->merge(magazines);