Php Math Help

[richo89]

Hi, I'm trying to use PHP math to create maths questions and test the user.

 

I'm currently generating random numbers and asking the user to add the two numbers, I then want to check if the answer is correct. However, when I click submit the random numbers change as page refreshes and therefore my variable changes so it keeps saying incorrect answer.

 

Code is below:

 

<?php

// Question 1.
$number1 = rand(1,10);
$number2 = rand(5,15);
$answer1 = $number1 + $number2;

echo "<p>";
echo "<b>Q1.</b> $number1 + $number2 = <form name='answer1form' method='post' action='index.php'> <input type='text' size='1' name='answer1'/>";
echo "</p>";

echo "<input type='submit' name='Submit' value='Submit'>";

if($_POST['Submit']){

echo "<p>";
echo $_POST['answer1'];
echo "</p>";

echo "<p>";
echo $answer1;
echo "</p>";

if ($_POST['answer1'] == $answer1)
{
echo "<p>Correct answer</p>";
}
else
{
echo "<p>Incorrect answer</p>";
}

}
echo "</form>";
?>

[PFMaBiSmAd]

The only thing that ties any HTTP requests together is what the browser supplies when it makes the HTTP request.

 

You would either need to pass the answer in a hidden field in the form (not secure), in a COOKIE (not secure) or using session variables on the server.

[Lamez]

<?php
session_start();
// Question 1.
$_SESSION['num1'] = $number1 = rand(1,10);
$_SESSION['num2'] = $number2 = rand(5,15);
$_SESSION['ans'] = $answer1 = $number1 + $number2;

echo "<p>";
echo "<b>Q1.</b> $number1 + $number2 = <form name='answer1form' method='post' action='index.php'> <input type='text' size='1' name='answer1'/>";
echo "</p>";

echo "<input type='submit' name='Submit' value='Submit'>";

if($_POST['Submit']){

echo "<p>";
echo $_POST['answer1'];
echo "</p>";

echo "<p>";
echo $_SESSION['ans'];
echo "</p>";

if ($_POST['answer1'] == $_SESSION['ans'])
{
echo "<p>Correct answer</p>";
}
else
{
echo "<p>Incorrect answer</p>";
}

}
echo "</form>";
?>

[richo89]

Thanks for the help just tried the above code but it still seems to refresh the variables each time so I keep getting incorrect answer.

[PFMaBiSmAd]

That's because the code is unconditionally assigning the values to the session variables, so they will be replaced on each page request.

 

You need to separate your form code from your form processing code -

if($_POST['Submit']){
    // code to process the form goes here
} else {
    // code to produce the form goes here, including setting any session variables you expect to have a specific value when the form is processed 
}

[richo89]

Ok so when I click submit the IF needs to process the form which is checking if the answer equals user input.

 

the ELSE produces the form, so by this do you mean the form name, method etc.

 

[richo89]

Can anyone try and help me further i'd be very grateful..

[PFMaBiSmAd]

One way to accomplish what you are doing -

<?php
session_start();
if(isset($_POST['Submit'])){
// code to process the form goes here
echo "<p>";
echo $_POST['answer1'];
echo "</p>";

echo "<p>";
echo $_SESSION['answer1'];
echo "</p>";

if ($_POST['answer1'] == $_SESSION['answer1'])
{
	echo "<p>Correct answer</p>";
} else {
	echo "<p>Incorrect answer</p>";
}
} else {
// code to produce the form goes here, including setting any session variables you expect to have a specific value when the form is processed 
$_SESSION['number1'] = $number1 = rand(1,10);
$_SESSION['number2'] = $number2 = rand(5,15);
$_SESSION['answer1'] = $number1 + $number2;
echo "<p>";
echo "<b>Q1.</b> $number1 + $number2 = <form name='answer1form' method='post' action=''>
		<input type='text' size='1' name='answer1'/>";
echo "</p>";
echo "<input type='submit' name='Submit' value='Submit'>";
echo "</form>";
}
?>

[richo89]

Thank you kindly it works perfectly, i'll try figure it out now and further it. Thanks again, PFMaBiSmAd.