如何從3D數組內部數據中創建列表PHP

Question

下面是數組的代碼。我試圖列出內部數組中的字段類別，並且當該字段爲空時寫入「無類別」。而我根本做不到。我一直試圖用兩個foreach嵌套將列表保存到一個新的數組中，但我不能完全正確地使用它。

 Array(
'type' => 'success', 
'value => array (
    0 => array (
     'id' => 1, 
     'joke' => 'Chuck Norris uses ribbed condoms inside out, so he gets the pleasure.', 
      'categories' => array()); 
    1 => array (
      'id' => 2, 
      'joke' => 'MacGyver can build an airplane out of gum and paper clips. Chuck Norris can kill him and take it.', 
      'categories' => array(    
      [0] => nerdy       
      )); 
     2 => array (
      'id' => 3, 
      'joke' => 'MacGyver can build an airplane out of gum and paper clips. Chuck Norris can kill him and take it.', 
      'categories' => array(    
      [0] => explicit 
      )); 
    ); 
) 

//這是我想沒有運氣

$output = array(); 

    foreach($response as $row){ 
     foreach($row as $cat){ 
      $output[] = $cat['categories']; 
     } 
    } 

謝謝！

Answer 1

首先，數組中有錯誤的語法，分號代替逗號和方括號中的數組鍵。這是正確的語法。

$response = Array(
    'type' => 'success', 
    'value' => array (
     0 => array ('id' => 1, 'joke' => 'Chuck Norris uses ribbed condoms inside out, so he gets the pleasure.', 'categories' => array()), 
     1 => array ('id' => 2, 'joke' => 'MacGyver can build an airplane out of gum and paper clips. Chuck Norris can kill him and take it.', 
      'categories' => array(0 => 'nerdy')), 
     2 => array (
      'id' => 3, 
      'joke' => 'MacGyver can build an airplane out of gum and paper clips. Chuck Norris can kill him and take it.', 
      'categories' => array(
      0 => 'explicit')))); 

現在輸出。你想要一個輸出，其中'沒有類別'字段將是一個字符串，對不對？所以結果數組的print_r看起來像這樣。

Array 
(
    [0] => without category 
    [1] => Array 
     (
      [0] => nerdy 
     ) 

    [2] => Array 
     (
      [0] => explicit 
     ) 

) 

如果是的話，這裏是你如何解開你的數組。

foreach($response as $row) { 
    if (is_array($row)) { 
     foreach($row as $cat) { 
      if (empty($cat['categories'])) { 
       $output[] = 'without category'; 
      } else { 
       $output[] = $cat['categories']; 
      } 
     } 
    } 
}