PHP检查是否单击了单选按钮

Question

I want to know if the user clicks the submit button, it will check if the user checks all radiobuttons.

This is what I've tried so far:

  $stmt = $conn->prepare( "SELECT *
      FROM tblquiz ORDER BY rand()" );
      $stmt->execute();

  ?>
  <form method="post" action="checkquiz.php">
    <?php 
    $number = 0;
    for($i=0; $row = $stmt->fetch(); $i++){
            $number++;  
            $id = $row['_id'];
            $question = $row['question'];
            $answers = array($row['answer1'],$row['answer2'],$row['answer3'],$row['correctanswer']);
            shuffle($answers);
    ?>

     <h4> <?php echo $number . ".) " . $question; ?></h4>   
     <label><input type="radio" value="<?php echo $answers[0]; ?>" name="<?php echo $question; ?>"> <?php echo $answers[0]; ?></label>
     <label><input type="radio" value="<?php echo $answers[1]; ?>" name="<?php echo $question; ?>"> <?php echo $answers[1]; ?></label>
     <label><input type="radio" value="<?php echo $answers[2]; ?>" name="<?php echo $question; ?>"> <?php echo $answers[2]; ?></label>
     <label><input type="radio" value="<?php echo $answers[3]; ?>" name="<?php echo $question; ?>"> <?php echo $answers[3]; ?></label>

    <?php
    }
    ?>
    <br />
    <br />
    <input type="submit" value="Submit" name="submit">
</form>

CheckQuiz.php

<?php 


if( isset($_POST['submit'])) {
    //echo 'You clicked submit!';

    if(  ){

    } else {

    }


} else {

    echo "You didn't click submit!";

}


?>

Im a newbie so I really need your help. I want check first if all radio buttons have been checked and then check if the user's answers. Can you give me sample implementations of this? Your help will truly be appreciated Thanks.

Answer 1

First you have name all your radio buttons with the same name. Say its name is question. example below

<input type="radio" name="question" value="1">
<input type="radio" name="question" value="2">
<input type="radio" name="question" value="3">
<input type="radio" name="question" value="4">

Then you can access its value from server as

if(isset($_POST["question"])){   
   echo $_POST["question"]; 
}else{
  echo "No answers were selected";
}

edited as per needed by user

if you have multiple questions then you could use like below

Question 1:

<input type="radio" name="question[1]" value="1">
<input type="radio" name="question[1]" value="2">
<input type="radio" name="question[1]" value="3">
<input type="radio" name="question[1]" value="4">

Question 2:

<input type="radio" name="question[2]" value="1">
<input type="radio" name="question[2]" value="2">
<input type="radio" name="question[2]" value="3">
<input type="radio" name="question[2]" value="4">

Then you could iterate as below:

   $quest = $_POST['question'];
   foreach($quest as $key=>$val){
         echo "Question ".$key." answer is ".$val."<br/>";
   }