php - 如何将碳转换为字符串，仅取日期？

Question

我有一个这样的收藏

0 => array:4 [
  "so" => "SO-1"
  "product_name" => "EXTREME FORTE - BP"
  "created_at" => Carbon @1527481346 {#628
    date: 2018-05-28 04:22:26.0 UTC (+00:00)
  }
  "id" => "5b0b84027475aa1508002623"
]

如何只取“2018-05-28”？
有人可以帮我解决这个问题吗？不管怎么说，还是要谢谢你

Answer 1

$collection_item->created_at->format('Y-m-d');