CODEWITHSUNDEEP
phpsql
hemmo001
hemmo001

Reputation: 1

PHP multi choice quiz- how to show 20 random questions out of 80 questions

My website is now done and this is the last thing that needs to be sorted. I have added in 80 questions into the database. I have chose to focus on Fractions (adding, subtracting, multiplication and division).

The quiz shows all of the 80 and the results show on screen once the user has completed the quiz!

I need some advice, I want the quiz to generate just 20 ramdom questions from the database. How can this be done? I was talking to someone and he said I would have to have a counter (20) and an array to help with this - has anyone got any ideas?

This is the quiz code so far:

    <head>
    <link rel="stylesheet" type="text/css" href="/css/style.css" />
</head>
<?php
require 'core/init.php';
include('inc/pheader.php'); ?>

<?php

session_start();
if(isset($_GET['question'])){
    $question = preg_replace('/[^0-9]/', "", $_GET['question']);
    $next = $question + 1;
    $prev = $question - 1;
    if(!isset($_SESSION['qid_array']) && $question != 1){
        $msg = "Sorry! No cheating.";
        header("location: start.php?msg=$msg");
        exit();
    }
    if(isset($_SESSION['qid_array']) && in_array($question, $_SESSION['qid_array'])){
        $msg = "Sorry, Cheating is not allowed. You will now have to start over. Haha.";
        unset($_SESSION['answer_array']);
        unset($_SESSION['qid_array']);
        session_destroy();
        header("location: start.php?msg=$msg");
        exit();
    }
    if(isset($_SESSION['lastQuestion']) && $_SESSION['lastQuestion'] != $prev){
        $msg = "Sorry, Cheating is not allowed. You will now have to start over. Haha.";
        unset($_SESSION['answer_array']);
        unset($_SESSION['qid_array']);
        session_destroy();
        header("location: start.php?msg=$msg");
        exit();
    }
}
?>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Quiz Page</title>
<script type="text/javascript">
function countDown(secs,elem) {
    var element = document.getElementById(elem);
    element.innerHTML = "You have "+secs+" seconds remaining.";
    if(secs < 1) {
        var xhr = new XMLHttpRequest();
        var url = "userAnswers.php";
            var vars = "radio=0"+"&qid="+<?php echo $question; ?>;
            xhr.open("POST", url, true);
            xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            xhr.onreadystatechange = function() {
        if(xhr.readyState == 4 && xhr.status == 200) {
            alert("You did not answer the question in the allotted time. It will be marked as incorrect.");
            clearTimeout(timer);
    }
}
xhr.send(vars);
        document.getElementById('counter_status').innerHTML = "";
        document.getElementById('btnSpan').innerHTML = '<h2>Times Up!</h2>';
        document.getElementById('btnSpan').innerHTML += '<a href="quiz.php?question=<?php echo $next; ?>">Click here now</a>';

    }
    secs--;
    var timer = setTimeout('countDown('+secs+',"'+elem+'")',1000);
}
</script>
<script>
function getQuestion(){
    var hr = new XMLHttpRequest();
        hr.onreadystatechange = function(){
        if (hr.readyState==4 && hr.status==200){
            var response = hr.responseText.split("|");
            if(response[0] == "finished"){
                document.getElementById('status').innerHTML = response[1];
            }
            var nums = hr.responseText.split(",");
            document.getElementById('question').innerHTML = nums[0];
            document.getElementById('answers').innerHTML = nums[1];
            document.getElementById('answers').innerHTML += nums[2];
        }
    }
hr.open("GET", "questions.php?question=" + <?php echo $question; ?>, true);
  hr.send();
}
function x() {
        var rads = document.getElementsByName("rads");
        for ( var i = 0; i < rads.length; i++ ) {
        if ( rads[i].checked ){
        var val = rads[i].value;
        return val;
        }
    }
}
function post_answer(){
    var p = new XMLHttpRequest();
            var id = document.getElementById('qid').value;
            var url = "userAnswers.php";
            var vars = "qid="+id+"&radio="+x();
            p.open("POST", url, true);
            p.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            p.onreadystatechange = function() {
        if(p.readyState == 4 && p.status == 200) {
            document.getElementById("status").innerHTML = '';
            alert("Thanks, Your answer was submitted"+ p.responseText);
            var url = 'quiz.php?question=<?php echo $next; ?>';
            window.location = url;
    }
}
p.send(vars);
document.getElementById("status").innerHTML = "processing...";

}
</script>
<script>
window.oncontextmenu = function(){
    return false;
}
</script>
</head>

<body onLoad="getQuestion()">
<div id="status">
<div id="counter_status"></div>
<div id="question"></div>
<div id="answers"></div>
</div>
<script type="text/javascript">countDown(45,"counter_status");</script>
</body>
</html>

Upvotes: 0

Views: 8181

Answers (2)

bish
bish

Reputation: 3419

What's your database? I assume MYSQL? Then this select-statement will probably help you.

It won't produce duplicates:

select * from my_question_table order by rand() limit 0,20;

It will select everything (*) from the table "my_question_table", order the result randomly and select the first 20 rows.

edit: Just saw the comment from TJ. As he was faster than me he deserves the reputation.

Upvotes: 1

Alexander Craggs
Alexander Craggs

Reputation: 8819

Let me start by saying I have never done a line of PHP in my life, so this might not work.

Try this: 

 for ($i = 1; $i <= 20; $i++) {
     $var = rand(1,80);
     //code to get answer from SQL database.
 }

Duplicates may occur with this code. I would use an array to stop this, but I have absolutely no idea how to create one. In sudo code:

define array called "array"
start for statement to count 20 times.
start nested for statement
check if this random number is the same as any other in the array
if not, continue
if so, variable in for statement = value - 1 (for above code, the variable is called i)
get random number and add it to the array.

Upvotes: 0

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