提取值了stdClass的对象

Question

我var_dump的变量$results的说明是这样的

array (size=11) 
    0 => 
    object(stdClass)[69] 
     public 'Tables_in_database-name-here' => string 'wp_commentmeta' (length=14) 
    1 => 
    object(stdClass)[68] 
     public 'Tables_in_database-name-here' => string 'wp_comments' (length=11) 
    2 => 
    object(stdClass)[67] 
     public 'Tables_in_database-name-here' => string 'wp_links' (length=8) 

    ... 

    10 => 
    object(stdClass)[59] 
     public 'Tables_in_database-name-here' => string 'wp_users' (length=8) 

我希望能在提取表名了上述的结构，并列出它们像这样的逗号分隔形式;

`wp_commentmeta,wp_comments,wp_links....,wp_users` 

我得到了一个关于如何从这种结构中提取数据的脑冻结时刻。

我尝试了很多选择，因为你可以通过下面的代码来关注它 - 每个结尾的错误！

foreach ($results as $current_item): 
     /* 
     * $current_item is something like this: 
     * 
     * object(stdClass)[69] 
      public 'Tables_in_database-name-here' => string 'wp_commentmeta' (length=14) 
     */ 

     # echo $current_item;  
     # fires an error as "Catchable fatal error: Object of class stdClass could not be converted to string" 

     # echo $current_item[1]; 
     # fires an error as "Cannot use object of type stdClass as array in..." 

     # echo array_values($current_item); 
     # fires an error as "array_values() expects parameter 1 to be array, object given in .." 

     # echo $current_item['Tables_in_database-name-here']; 
     #fires an error as "Cannot use object of type stdClass as array in " 

     how do you get that darn thing? :) 

    endforeach; 

Answer 1

你的主要问题是属性名称Tables_in_database-name-here不能经由通常的$obj->propertyName手段来表示。 PHP允许您通过$obj->{'invalid-variable-name-but-ok-as-a-property'}使用字符串属性名称。

我只是通过implode()和array_map()构建字符串，如

$string = implode(',', array_map(function($result) { 
    return $result->{'Tables_in_database-name-here'}; 
}, $results)); 

演示〜https://eval.in/172247

关于属性名称，你也可以投stdclass对象的数组。例如...

$associativeArray = (array) $result; 
// array(1) { ["Tables_in_database-name-here"] => string(14) "wp_commentmeta" } 

$indexedArray = array_values($associativeArray); 
// array(1) { [0] => string(14) "wp_commentmeta" }