[RESOLVED] Incrementing a Random integer using rand()

cybastud

Im using the rand() function to generate a random integer. Every time the page refreshes I want the new random number to be added to the previously generated random number, thus creating a running total of randomly generated numbers...this is what I have so far but its not working...any assistance will be much appreciated

<?php

$random = rand();
echo "The random number is ".$random;
echo "<br>";
echo "<br>";

$newRandom += $random;

echo "The random number is now ".$newRandom;

?>

Thanks🙂

johanafm

You need to somehow retain values between page loads. Either keep forwarding the current value to the next page (but keep in mind that the user could manipulate this value before send the next post request) or use sessions to store the value server side. See [man]session_start[/man]

cybastud

Thanks. This is what I came up with so far

<?php

$random = rand();
$newRandom = 0;
echo "The random number is ".$random;
echo "<br>";
echo "<br>";

session_start(); // start a session
$_SESSION['random'] = "$random";
if(isset($_SESSION['random'])){ // check if the random number is stored in the session
	    $newRandom += $random;
		echo $newRandom;
	}
//$newRandom += $random;
echo "<br>";
echo "<br>";
//echo "The random number is now "//.$newRandom;

?>

It does echo out the $newRandom but it is the same value as $random. Any ideas?

Derokorian

$random = rand(); 
$newRandom = 0; 
echo "The random number is ".$random; 
echo "<br>"; 
echo "<br>"; 

session_start(); // start a session

PHP.net wrote:
To use cookie-based sessions, session_start() must be called before outputing anything to the browser.

Solution call session_start(); before you do anything else.

$_SESSION['random'] = "$random"; 
if(isset($_SESSION['random'])){ // check if the random number is stored in the session 
        $newRandom += $random; 
        echo $newRandom; 
    }

Here you set $_SESSION['random'] to the newly generated random number, then you check to see if it's set (which of course it is you just set it) then you add the newly generated number to 0 (which is what you previously set $newRandom to) and expect it to not be the same. For all x: x+0 = x

You may try something along these lines:

<?php

session_start();

$rand = rand();
echo 'The random number is: '.$rand.'<br><br>';

if( isset($_SESSION['rand']) ) {
   $_SESSION['rand'] += $rand;
} else {
   $_SESSION['rand'] = $rand;
}

echo 'You running total is: '.$_SESSION['rand'];

cybastud

Great! it works, thanks🙂

and Thanks for the explanation as well 🙂