json_encode在數組上返回null

Question

我想要json_encode一個php數組，但「選擇」部分返回null。

Array ([indexer] => 7 [section] => 1 [question] => What does the last paragraph indicate about an optimistic perspective? [answer] => a [choices] => There has never been a culture or religion that is genuinely optimistic`It is 「a riddle of the universe」`No enlightened culture sees the world in a truly optimistic manner`Optimistic perspectives are only held by the weak) 

{"indexer":"7","section":"1","question":"What does the last paragraph indicate about an optimistic perspective?","answer":"a","choices":null} 

有什麼想法爲什麼？

編輯：全碼：

$check = mysqli_query($con, "select * from questions where section = '$section' and indexer = '$question'"); 
$result = mysqli_fetch_array($check, MYSQLI_ASSOC); 

print_r($result); 
echo json_encode($result); 

Answer 1

json_encode期望你編碼爲有效的UTF-8的所有內容。如果內容的任何部分是不妥當的UTF-8，json_encode將失敗默默的那部分（B

所有字符串數據必須是UTF-8編碼。

我的猜測是， 「馬克未正確UTF-8編碼的（但是從CP1252基於編碼起源）。

參見json_last_error從JSON模塊檢索最後錯誤代碼。