Add value to new collection - arrays

Question

I have created a new collection, when I try to add new values with a key in a foreach loop its not working. It only appends the 1st value. I want it to add all.
Here my code:
$new = new Collection();
foreach($messages as $message){
$new['message'] = $message->message;
}
But in the end instead of returning all messages, it only returns the 1st message:
{"message":"first"}
Instead it should have returned
{"message": "first", "message": "second"}
What is the problem?
Also when I do it without giving a key to a collection, it returns all:
foreach($messages as $message){
$new = $message->message;
}

Answer 1

You have an array with the same key, so the for loop overrides the same value again and again.
If you want a collection that contains objects with the same key you can change the following code to your need:
$new = array();
foreach ([1, 2, 3] as $i) {
$new[] = array('message' => $i);
}
$collection = collect($new);

Answer 2

Your making a collection with 1 key: namely "message" and then proceed to overwrite this key for the duration of your loop. PHP thus handles this as shown in your question: a collection with 1 key and 1 value.
This makes perfect sense (for example, how many houses are on your home address? Only one right? What would happen to your mail if there were 16 houses with the exact same address?).
What you want simply isn't possible: how should PHP know what it should return when you ask for the value at "message" if the entire data structure would consist out of the same key?

Answer 3

test this code :
$messages=['ali','reza','sara'];
$new = new Collection();
foreach($messages as $key=>$message){
$new->prepend($message,$key);
}
dd($new);
output :
Collection {#475 ▼
#items: array:3 [▼
2 => "sara"
1 => "reza"
0 => "ali"
]
}