如何删除集合中的重复项？

Question

我收集了Laravel:

Collection {#450 ?
  #items: array:2 [?
    0 => Announcement {#533 ?}
    1 => Announcement {#553 ?}
  ]
}

这是相同的项目.如何删除其中一个？

完整代码是:

public function announcements()
    {

        $announcements = $this->categories_ann->map(function ($c) {
            return $c->announcements->map(function ($a) {
                $a->subsribed = true;

                return $a;
            });
        });

        $flattened = $announcements->groupBy("id")->flatten();

        return $flattened;
    }

Answer 1

$collection = collect([
    ['name' => 'iPhone 6', 'brand' => 'Apple', 'type' => 'phone'],
    ['name' => 'iPhone 5', 'brand' => 'Apple', 'type' => 'phone'],
    ['name' => 'Apple Watch', 'brand' => 'Apple', 'type' => 'watch'],
    ['name' => 'Galaxy S6', 'brand' => 'Samsung', 'type' => 'phone'],
    ['name' => 'Galaxy Gear', 'brand' => 'Samsung', 'type' => 'watch'],
]);

然后假设您希望品牌独一无二，在这种情况下，您应该只获得“Apple”和“Samsung”两个品牌

$unique = $collection->unique('brand');

$unique->values()->all();
/*
    [
        ['name' => 'iPhone 6', 'brand' => 'Apple', 'type' => 'phone'],
        ['name' => 'Galaxy S6', 'brand' => 'Samsung', 'type' => 'phone'],
    ]
*/

这取自https://laravel.com/docs/master/collections#method-unique

Answer 2

$unique = $collection->unique();