如何在 symfony 中对对象进行排序？答案

【问题标题】：How can I sort an object in symfony?如何在 symfony 中对对象进行排序？
【发布时间】：2019-01-02 15:51:31
【问题描述】：

这是“字段”

{#751 ▼
  +"id": array:9 [▼
    "fieldName" => "id"
    "type" => "integer"
    "scale" => 0
    "length" => null
    "unique" => true
    "nullable" => false
    "precision" => 0
    "id" => true
    "columnName" => "id"
  ]
  +"username": array:8 [▼
    "fieldName" => "username"
    "type" => "string"
    "scale" => 0
    "length" => 25
    "unique" => true
    "nullable" => false
    "precision" => 0
    "columnName" => "username"
  ]
  +"unique_id": array:8 [▼
    "fieldName" => "unique_id"
    "type" => "string"
    "scale" => 0
    "length" => 10
    "unique" => true
    "nullable" => false
    "precision" => 0
    "columnName" => "unique_id"
  ]
  +"password": array:8 [▼
    "fieldName" => "password"
    "type" => "string"
    "scale" => 0
    "length" => 64
    "unique" => false
    "nullable" => false
    "precision" => 0
    "columnName" => "password"
  ]
  +"email": array:8 [▼
    "fieldName" => "email"
    "type" => "string"
    "scale" => 0
    "length" => 191
    "unique" => true
    "nullable" => false
    "precision" => 0
    "columnName" => "email"
  ]
  +"isActive": array:8 [▼
    "fieldName" => "isActive"
    "type" => "boolean"
    "scale" => 0
    "length" => null
    "unique" => false
    "nullable" => false
    "precision" => 0
    "columnName" => "is_active"
  ]
}

我希望用户名总是在开头，密码总是在结尾。

这是我的方法：

  usort($fields, function ($a, $b) {  if ($a['fieldName'] == 'username' || $b['fieldName'] == 'password') return -1;
        elseif ($a['fieldName'] == 'password' || $b['fieldName'] == 'username') return 1;
        else return 0;
      });

但我收到一条错误消息：

警告：usort() 期望参数 1 是数组，给定对象

【问题讨论】：

@Thefourthbird 这给出了错误Cannot pass parameter 1 by reference
然后先将其转换为数组$fields = (array)$fields; usort($fields
或者您可以使用$fields = json_decode(json_encode($fields), true); 以不同的方式转换为数组

标签： php arrays symfony oop usort

【解决方案1】：

usort的第一个参数应该是一个数组，$fields是一个对象。一种选择是将其转换为如下数组：

$fields = (array)$fields;

然后传给usort：

usort($fields, function ($a, $b) {
    if ($a['fieldName'] == 'username' || $b['fieldName'] == 'password') return -1;
    elseif ($a['fieldName'] == 'password' || $b['fieldName'] == 'username') return 1;
    else return 0;
});

【讨论】：