How to unset (remove) a collection element after fetching it? - laravel

Question

I have a collection which I want to iterate and modify while I fetch some of its elements. But I could't find a way or method to remove that fetched element.
$selected = [];
foreach ($collection as $key => $value) {
if ($collection->selected == true) {
$selected[] = $value;
unset($value);
}
}
This is just a representation of my question for demonstration.
After #Ohgodwhy advice the forget() function I checked it again and saw that I actually misunderstood the function. It was exactly as I was looking for.
So for working solution I have added $collection->forget($key) inside the if statement.
Below is the working solution of my problem, using #Ohgodwhy's solution:
$selected = [];
foreach ($collection as $key => $value) {
if ($collection->selected == true) {
$selected[] = $value;
$collection->forget($key);
}
}
(this is just a demonstration)

Answer 1

You would want to use ->forget()
$collection->forget($key);
Link to the forget method documentation

Answer 2

Or you can use reject method
$newColection = $collection->reject(function($element) {
return $item->selected != true;
});
or pull method
$selected = [];
foreach ($collection as $key => $item) {
if ($item->selected == true) {
$selected[] = $collection->pull($key);
}
}

Answer 3

Laravel Collection implements the PHP ArrayAccess interface (which is why using foreach is possible in the first place).
If you have the key already you can just use PHP unset.
I prefer this, because it clearly modifies the collection in place, and is easy to remember.
foreach ($collection as $key => $value) {
unset($collection[$key]);
}

Answer 4

I'm not fine with solutions that iterates over a collection and inside the loop manipulating the content of even that collection. This can result in unexpected behaviour.
See also here: https://stackoverflow.com/a/2304578/655224 and in a comment the given link http://php.net/manual/en/control-structures.foreach.php#88578
So, when using foreach it seems to be ok but IMHO the much more readable and simple solution is to filter your collection to a new one.
/**
* Filter all `selected` items
*
* #link https://laravel.com/docs/7.x/collections#method-filter
*/
$selected = $collection->filter(function($value, $key) {
return $value->selected;
})->toArray();

Answer 5

If you know the key which you unset then put directly by comma
separated
unset($attr['placeholder'], $attr['autocomplete']);

Answer 6

You can use methods of Collection like pull, forget, reject etc.
But every Collection method returns an entirely new Collection instance.
Doc link: https://laravel.com/docs/8.x/collections#introduction