Laravel PHP foreach（User :: all（）as $ user）性能

if I write a foreach loop like this, is the method all() called every loop again or only once?

foreach(User::all() as $user) { ... }

In C# I know, the all() function is only executed once. But in php also?

Or is it faster if I hold the data in a variable like this?

$users = User::all();
foreach($users as $user) { ...}

Both pieces of code will do the exactly same job and will create just one DB query, but I'd go with this for better readability:

$users = User::all();
foreach ($users as $user) { ... }