my php quizz application not working when inserting question - php

Question

I have created a simple quizz application in php mysql. This application has two parts one is for students and other part is for admin, so in admin area I have created addquestion page here is the code
<form class="form-horizontal " action="addquestion.php" method="post" style="width:50%;margin:0 auto" id="addquestionform">
<div class="form-group">
<label class="control-label col-sm-3" for="q">Question</label>
<div class="col-sm-9">
<input type="text" class="form-control" id="q" placeholder="Enter Question" name="q">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="ch1">Choice 1</label>
<div class="col-sm-9">
<input type="text" class="form-control" id="ch1" placeholder="Enter choice 1" name="ch1">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="ch2">Choice 2</label>
<div class="col-sm-9">
<input type="text" class="form-control" id="ch2" placeholder="Enter Choice 2" name="ch2">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="ch3">Choice 3</label>
<div class="col-sm-9">
<input type="text" class="form-control" id="ch3" placeholder="Enter choice 3" name="ch3">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="ch4">Choice 4</label>
<div class="col-sm-9">
<input type="text" class="form-control" id="ch4" placeholder="Enter choice 4" name="ch4">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="cn">Correct Choice</label>
<div class="col-sm-9">
<input type="number" class="form-control" id="cc" placeholder="Enter correct choice" name="cc">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="cn">Choose Catogry</label>
<div class="col-sm-9">
<select class="pull-left form-control" name="cat">
<?php while($row = mysqli_fetch_assoc($category)){ ?>
<option value="<?php echo $row['id']; ?>"><?php echo $row['subject_name']; ?> </option>
<?php } ?>
</select>
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-3 col-sm-10">
<button type="submit" class="btn btn-default">Add Question</button>
</div>
</div>
</form>
for php part the code is as following where i get values from form for example the question, choice 1, choice 2, choice 3, choice 4 , correct choice, and the category where question and choices will be added .
if($_SERVER["REQUEST_METHOD"] == "POST"){
$question = $_POST['q'];
$choices[1] = $_POST['ch1'];
$choices[2] = $_POST['ch2'];
$choices[3] = $_POST['ch3'];
$choices[4] = $_POST['ch4'];
$correct = $_POST['cc'];
$cat = $_POST['cat'];
$query = mysqli_query($con,"insert into subject_questions values('','$question','$cat')");
if($query){
$questionid = mysqli_insert_id($con);
echo $questionid;
foreach($choices as $key => $value){
if($key == $correct){
$correct = 1;
}else{
$correct = 0;
}
$insert = mysqli_query($con,"insert into objectives values('','".$correct."','".$value."','".$questionid."')") or die(mysqli_error());
}
if($insert){
echo " <script> alert('question added successfully'); </script> ";
}else{
echo " <script> alert('question not added'); </script> ";
}
}
}
$category = mysqli_query($con,"select * from subject_category");
Now the problem is when the question and choices gets added to database only the first choice is selected as correct if its correct for example if some other choice is correct it does not put 1 as correct option there it only works for first choice I am guessing the problem lies here in this following part, here I used for each loop to loop through choices which comes from form and then stored inside $choices array so I check to see if key is match with the correct value entered in form if its correct then the correct variable gets 1 and if its not then its gets 0 . so as mentioned it only gets 1 if the first choice is correct but not for other choices .
foreach($choices as $key => $value){
if($key == $correct){
$correct = 1;
}else{
$correct = 0;
}
$insert = mysqli_query($con,"insert into objectives values('','".$correct."','".$value."','".$questionid."')") or die(mysqli_error());
}

Answer 1

The problem is that you're reusing the variable name $correct. At first it contains the number of the correct answer, but then you assign 1 or 0 to it. On the next iteration, when you do:
if ($key == $correct)
it no longer holds the number of the correct answer.
Use different variables.
foreach($choices as $key => $value){
if($key == $correct){
$is_correct = 1;
}else{
$is_correct = 0;
}
$insert = mysqli_query($con,"insert into objectives values('','".$is_correct."','".$value."','".$questionid."')") or die(mysqli_error());
}

Answer 2

It seems you are overriding the value of $correct inside the loop. Which failes for correct answer except 1; reomve overriding the variable $correct and rewrite the code.
instead of writing
foreach($choices as $key => $value){
if($key == $correct){
$correct = 1;
}else{
$correct = 0;
}
$insert = mysqli_query($con,"insert into objectives values('','".$correct."','".$value."','".$questionid."')") or die(mysqli_error());
}
you can write
foreach($choices as $key => $value){
if($key == $correct){
$insert = mysqli_query($con,"insert into objectives values('','1','".$value."','".$questionid."')") or die(mysqli_error());
}else{
$insert = mysqli_query($con,"insert into objectives values('','0','".$value."','".$questionid."')") or die(mysqli_error());
}
}
for example
if you are taking value of $correct as other than 1, after first iteration $correct resets to 0 and for the rest of the loop it carries value of 0.