php - 数组去重 0 1 2 中id相同 保留0下标 重新组装数据 --- 类似于未读消息叠加 求方法

Question

[0]=>
  array(4) {
    ["id"]=>
    string(3) "591"
    ["face"]=>
    string(47) "/Public/logo.png"
    ["content"]=>
    string(6) "来吧"
    ["cnname"]=>
    string(5) "qwert"
  }
  [1]=>
  array(4) {
    ["id"]=>
    string(3) "591"
    ["face"]=>
    string(47) "/Public/logo.png"
    ["content"]=>
    string(9) "吃了没"
    ["cnname"]=>
    string(5) "qwert"
  }
 [3]=>
  array(4) {
    ["id"]=>
    string(3) "591"
    ["face"]=>
    string(47) "/Public/logo.png"
    ["content"]=>
    string(9) "吃了44没"
    ["cnname"]=>
    string(5) "qwer44"
  }
  [4]=>
  array(4) {
    ["id"]=>
    string(3) "588"
    ["face"]=>
    string(47) "/Public/logo.png"
    ["content"]=>
    string(12) "中华订单"
    ["cnname"]=>
    string(18) "刚好惊喜交加"
  }
  [5]=>
  array(4) {
    ["id"]=>
    string(3) "542"
    ["face"]=>
    string(77) "/Public/uploads/images/user/20170213453878.jpg"
    ["content"]=>
    string(9) "你啥时"
    ["cnname"]=>
    string(6) "qwe123"
  }

Answer 1

    <?php
    $arr = array(
              0 => array(
                      'id'      => '591',
                      'face'    => '/Public/logo.png',
                      'content' => '来吧',
                      'cnname'  => 'qwert',
    
                ),
              1 => array(
                      'id'      => '591',
                      'face'    => '/Public/logo.png',
                      'content' => '吃了没',
                      'cnname'  => 'qwert',
    
                ),
            2 => array(
                      'id'      => '591',
                      'face'    => '/Public/logo.png',
                      'content' => '吃了44没',
                      'cnname'  => 'qwert',
    
                ),
            4 => array(
                      'id'      => '592',
                      'face'    => '/Public/logo.png',
                      'content' => '吃了44没',
                      'cnname'  => 'qwert',
    
                ),
      );
    
    $result = array();
    foreach ($arr as $key => $value) {
      if(empty($value)) {
          continue;
      }
      $value['content'] = (array)$value['content'];
      if(isset($result[$value['id']])) {
        $k = key($result[$value['id']]);
        $result[$value['id']][$k]['content'] = array_merge($result[$value['id']][$k]['content'], $value['content']);
        
      }else {
        $result[$value['id']][$key] = $value;
      }
    }
    
    var_dump(current($result));die;