LARAVEL : Add key and value in single array - php

Question

I have a single array of data, I want to add a key and it's value in same array . Here in addedPost I want to add key favouritePost and it's value is $favouritePost after product key. How can i do this ?
Here is my query:
$addedPost = Post::with(['product','postattribute.attribute.category','user.userDetails'])
->whereId($postData['post_id'])
->first();
$favouritePost = PostFavourite::isAlreadyAdded($postData['post_id'], Auth::id());
return [
'status_code' => $status_code,
'message' => $message,
'PostDetails' => $addedPost
];
What I get in response :
{
"PostDetails": {
"id": 289,
"user_id": 12,
"product_id": 2,
"demand_or_supply": "Demand",
"description": "edited1",
"status": "Expired",
"created_at": "2018-06-22 07:35:27",
"updated_at": "2018-07-05 06:42:56",
"product": {
"id": 2,
"title": "Diamond",
"icon": null,
"status": "Active"
}
}
}
EXPECTED RESULT:
{
"PostDetails": {
"id": 289,
"user_id": 12,
"product_id": 2,
"demand_or_supply": "Demand",
"description": "edited1",
"status": "Expired",
"created_at": "2018-06-22 07:35:27",
"updated_at": "2018-07-05 06:42:56",
"product": {
"id": 2,
"title": "Diamond",
"icon": null,
"status": "Active"
},
"favouritepost": {
"id": 8,
"post_id": 289,
"user_id": 12
}
}
}

Answer 1

First: Your $addedPost is not an array but a Eloquent Collection. There are multiple possibilites to do this. The easiest one is to union an Array with the Collection.
$union = $addedPost->union($favouritePost->toArray());
For every other solution please take a look at the Laravel Documentation. It's pretty easy to understand.
https://laravel.com/docs/5.6/collections
Edit: Though I missed the ->first() inside the question just use the solution already mentioned. ->first() returns a StdClass Object, so you can handle it like it:
$addedPost->favouritepost = $favouritePost;
That property favouritePost is added to $addedPost object in that case. There's no need for any method call again.

Answer 2

first you store all the values which you are returning in one associative array then use array_push() to add new key/value in that array.After all you just return that array.

Answer 3

Assuming that $addedPost is a laravel collection you can simply do:
$addedPost = Post::with(['product','postattribute.attribute.category','user.userDetails'])
->whereId($postData['post_id'])
->first();
$favouritePost = PostFavourite::isAlreadyAdded($postData['post_id'], Auth::id());
$addedPost->put('favouritepost', $favouritePost);
return [
'status_code' => $status_code,
'message' => $message,
'PostDetails' => $addedPost
];

Answer 4

for adding key value in object
$object->new_key="value";