数组（['1'] => 1）1注意：未定义的偏移量：第152行的C：\\ xampp \\ htdocs \\ HR \\ functions \\ functions_applicants.php中的1

Question

The code below is to display the quiz(questions and answers)

When submitting, I am getting error:

"Array ( ['1'] => 1 ) 1
Notice: Undefined offset: 1 in C:\xampp\htdocs\HR\functions\functions_applicants.php on line 152
2". 



<form method="post" action="index.php?results">

<?php 

for($i=1; $i<27; $i++) {

$query = query("SELECT * FROM assess_questions WHERE question_id =$i");
confirm($query);

while($row = fetch_array($query)) {

?> 

<div>
<h4><?php echo $row['question']; ?></h4>

<input type="radio" name="quizcheck['<?php echo $row['question_id']; ?>']" 
value=1><?php echo $row['A']; ?><br>
<input type="radio" name="quizcheck['<?php echo  $row['question_id']; ?>']" 
value=2><?php echo $row['B']; ?><br>
<input type="radio" name="quizcheck['<?php echo  $row['question_id']; ?>']" 
value=3><?php echo $row['C']; ?><br>
<input type="radio" name="quizcheck['<?php echo  $row['question_id']; ?>']" 
value=4><?php echo $row['D']; ?><hr>
</div>

<?php 
}
}
?>

<input class="btn btn-info" type="submit" name="submit_answers" 
value="Next">

</form>

THIS IS THE FUNCTION TO CHECK FOR THE ANSWER. THIS IS WHERE IM GETTING THE ERROR FROM. ITS THE $i that's causing the error.

  if(isset($_POST['submit_answers'])) {

    $result = 0;
    $i = 1;
    $average = 0;

    $item = ($_POST['quizcheck']);
    print_r($item) ;

    $query = query("SELECT * FROM assess_questions");
    confirm($query);

    while($row = fetch_array($query)) {
      print_r($row['answer_id']);

      $checked = ($row['answer_id']) == $item[$i];

      if($checked) {

       $result++;

      }

      $i++;
     }

    }

Answer 1

you begin with $i = 1; in which case you'll avoid $item[0]; (first position) and it will mismatch $checked = ($row['answer_id']) .

start with $i=0; as if there's only one answer $i[1] will not exists but $i[0];

****EDIT**** first check your query result for not being void: example, having this db connection function/method:

  <?php
    function connection(){
        try{
            //host, user, passwd, DB name)
            $mysqli = new mysqli($host, $user, $passwd, $dbName);
            return $mysqli;
        }catch (Exception $mysqlin){
            echo "Error establishing connection with ddbb ".$mysqlin->getMessage(); 
        }
    }
    ?>

And modifying your code:

  if(isset($_POST['submit_answers'])) {

    $result = 0;
    //indexes must start at 0 unless you ensure that you don't need 0 value and your algorithm will not keep trying to get a value out of bounds / array offset
    $i = 0;
    $average = 0;

    //i assume that $_POST['quizcheck'] is an array, otherwise the $item[$i] will be an out of bounds, which match with your issue (array offset). But i ensured some parts of your structure below for you to learn:

    $item = ($_POST['quizcheck']);
    print_r($item) ;
    //you'll must prepare this statement after, for security
    $sql = query("SELECT * FROM assess_questions");
    //we get the result of this query on $result, if possible
    if($result = connection()->query($sql)){

    //we get the first row inside $rs (usually called Record Set) as associative (it means that you'll call the values as the column name on DB unless you use AS "Alias" on your query.
    $rs = mysqli_fetch_assoc($result);
   //if the record set is not void:
    while($rs!="") {
      //assuming that your DB col is called answer_id
      print_r($rs['answer_id']);
      //checked will get the value of matching those two arrays, so make sure you control nullables:
      if($checked = ($rs['answer_id']) == $item[$i]){
        //only if $checked value could be set 
           if($checked) {
               $result++;
           }
       }

      $i++;
     }
   //repeat this to get the next value, when it has no more values it will be void so it will escape from while loop.
   $rs = mysqli_fetch_assoc($result);
   }
 }

Never assume that you'll get always a value.

Never assume that users will put numbers in some input only because you told them to do it.

Never use dates without checking.

Never state an algorithm with not-controlled vars/function outputs.

Control all data all over across your code and comment it, it will help you to avoid issues and modify your code months after you coded it.

Hope it helps you. I recommend you to get a hosting to test/code in a controlled environment.

Answer 2

The clue is in the contents of $item which you have done a print_r on and got the result:

Array(['1'] => 1)

You're getting this result because in your html your radio buttons are labelled quizcheck['n'] where n is the question id. So presumably in this case you have pressed the first radio button in the first question. You should change the line which gives the radio buttons a name to

<input type="radio" name="quizcheck[<?php echo $row['question_id']; ?>]" value=1><?php echo $row['A']; ?><br>

(ie remove the single quotes around <?php echo $row['question_id']; ?> ). This will make $item look like:

Array ( [1] => 1 )

so the test

($row['answer_id']) == $item[$i];

will work. Note the parentheses around $row['answer_id'] are unnecessary.

The other issue you are going to run into is that your form obviously doesn't require the user to submit an answer to every question. This means that in your while loop you need to check whether the user has submitted an answer to be checked against the result. If you are not going to make it compulsory to answer all questions, you will need to put an array_key_exists check around the result checking code:

if (array_key_exists($i, $item)) {
    $checked = $row['answer_id'] == $item[$i];
    if ($checked) {
        $result++;
    }
}