PHP 通知 : undefined offset 381 and 382 with in while loop

Question

此代码显示类似 PHP Notice 的错误: undefined offset 381。并且偏移量随着循环运行而增加。

$marks=0;
$correct = 0;
while ($row=mysqli_fetch_assoc($result)){
    $exam_name = $row['exam_name'];
    $exam_percentage = $row['exam_pass_percentage'];
    if($row['a_sortorder'] == $json['responses'][0][1][$row['qid']]){
        $marks = $marks + 4;
        $correct++;
    }
}

不知道该怎么办？

Answer 1

将您的代码更改为:

$marks=0;
$correct = 0;
while ($row=mysqli_fetch_assoc($result)){
    $exam_name = $row['exam_name'];
    $exam_percentage = $row['exam_pass_percentage'];
    if(isset($row['a_sortorder']) && isset($json['responses'][0][1][$row['qid']]) && $row['a_sortorder'] == $json['responses'][0][1][$row['qid']]){
        $marks = $marks + 4;
        $correct++;
    }
}