Simple PHP quiz using a text box input - php

Question

I'm looking to implement a very simple quiz using PHP which I'm struggling to find any other examples of to copy. I'm open to various solutions but the requirements are as follows:
Quiz takes place on a single page;
One questions appears at a time, and the user can only see the next question when they correctly answered the current one;
All question types are 'short answer', with users needing to input the correct answer in a text box.
I have been attempting to find a solution using PHP conditional statements (if/else) based on a users answers and my current code looks like this:
<form method="POST" action="">
<label for="question01">1. How many sides does a triangle have?</label>
<input type="text" name="guess01" value="">
<input type="submit">
</form>
<?php
// Process Question 1 Form
$guess01 = $_POST['guess01'];
$guess01 = strtolower($guess01);
$answer01 = "three";
if ($guess01 == $answer01)
{
?>
<p>Correct answer given for question 1!</p>
<form method="POST" action="">
<label for="question02">2. How many sides does a square have?</label>
<input type="text" name="question02" value="" placeholder="Answer here...">
<input type="submit">
</form>
<?php
// Process Question 2 Form
$guess02 = $_POST['guess02'];
$guess02 = strtolower($guess02);
$answer02 = "four";
if ($guess02 == $answer02)
{
?>
<p>Correct answer given for question 2!</p>
<form>
<label for="question02">3. How many sides does a pentagon have?</label>
<input type="text" name="question02" value="" placeholder="Answer here...">
<input type="submit">
</form>
<?php
// Process Question 2 Form
$guess03 = $_POST['guess02'];
$guess03 = strtolower($guess02);
$answer03 = "five";
if ($guess03 == $answer03)
{
?>
<p>Correct answer given for question 3!</p>
<p>Quiz completed!</p>
<?php
}
elseif (empty($guess03))
{
echo "<!-- No Answer Given -->";
}
else
{
echo "<p>Try Again!</p>";
}
?>
<?php
}
elseif (empty($guess02))
{
echo "<!-- No Answer Given -->";
}
else
{
echo "<p>Try Again!</p>";
}
?>
<?php
}
elseif (empty($guess01))
{
echo "<!-- No Answer Given -->";
}
else
{
echo "<p>Try Again!</p>";
}
?>
I'm sure this is very inefficient coding and I'm open to other ways of tackling this. Any help would be very gratefully received. Thank you.

Answer 1

As the form and the validation of your questions are always same only the data changes, you do not need to copy the code. Just put questions and answers in an array and put the number of the current questions in your form.
// Declare all your questions and answers as multi dimensional array
$questionsAndAnwsers = array(array("question" => "1. How many sides does a triangle have?", "answer" => "three"),
array("question" => "2. How many sides does a square have?", "answer" => "four"));
// current question
$currentQuestion = 0;
if(isset($_POST["currentQuestion"])){
$currentQuestion = $_POST["currentQuestion"];
if($_POST["guess"] == $questionsAndAnwsers[$currentQuestion]["answer"]){
// answer was correct, increment your question-counter for the next question
$currentQuestion++;
// print success message
} else {
// question was wrong, counter stays as it is, so same question will be printed
// print failure message
}
}
?>
<form method="POST" action="">
<label for="question"><?php echo ($currentQuestion+1).". ". $questionsAndAnwsers[$currentQuestion]["question"];?></label>
<input type="hidden" name="currentQuestion" value="<?php echo $currentQuestion;?>">
<input type="text" name="guess" value="">
<input type="submit">
</form>
<?php
You have to add a additional if-clause, for the case all questions has been answered.
EDIT:
This is a simple Implementation and it is easy to cheat. As the question number is passed to the browser, the user can alter it (setting it to 9). To close this whole, you have to use session and save the number of the last correct answer in the session on the server.