PHP – $SESSION Variables – Eli the Computer Guy

Session Variables allow you to set Variable Values that can be accessed across all pages that your user goes to in your PHP Web Application.

You must use session_start() on all pages that will access or use Session Variables and then you can access the Variables from $_SESSION[‘variable_name’]

$_SESSION

home.php

<a href='/home.php'>Home</a>
<a href='/about.php'>About</a>
<a href='./anotherPage.php'>Another Page</a>
<a href='./logoutScript.php'> --- LOGOUT ---</a>
<br><br>

Please Log In:
<form action='loginScript.php' method='post'>
Name: <input type='text' name='username'>
Font Size: <input type='number' name='fontsize'>
<input type='submit'>
</form>

<?php

session_start();

$username = $_SESSION['username'];
$fontsize = $_SESSION['fontsize'];

echo "<strong>".$username."</strong> is logged in";

echo "<p style='font-size:".$fontsize.";'>This is text on the HOME PAGE.  Look at what the size is!!!</p>";

?>

loginScript.php

<a href='/home.php'>Home</a>
<a href='/about.php'>About</a>
<a href='./anotherPage.php'>Another Page</a>
<br><br>

<?php

session_start();

$_SESSION['username'] = $_POST['username'];
$_SESSION['fontsize'] = $_POST['fontsize'];

echo "You are now logged in as: ".$_SESSION['username']."<br>";
echo "You set the fontsize to: ".$_SESSION['fontsize']."<br>";
echo "Go to the Other Pages to see how SESSION VARIABLES Work";

?>

logoutScript.php

You have been logged out.
<br>
<a href='./home.php'>HOME</a>

<?php

session_start();

session_unset();

session_destroy();

?>

about.php

<a href='/home.php'>Home</a>
<a href='/about.php'>About</a>
<a href='./anotherPage.php'>Another Page</a>
<a href='./logoutScript.php'> --- LOGOUT ---</a>
<br><br>

<?php

session_start();

$username = $_SESSION['username'];
$fontsize = $_SESSION['fontsize'];

echo "<strong>".$username."</strong> is logged in";

echo "<p style='font-size:".$fontsize.";'>This is text on the ABOUT PAGE.  If I wasn't a mushroom I could write something here amazing!</p>";

?>

anotherPage.php

<a href='/home.php'>Home</a>
<a href='/about.php'>About</a>
<a href='./anotherPage.php'>Another Page</a>
<a href='./logoutScript.php'> --- LOGOUT ---</a>
<br><br>

<?php

session_start();

$username = $_SESSION['username'];
$fontsize = $_SESSION['fontsize'];

echo "<strong>".$username."</strong> is logged in";

echo "<p style='font-size:".$fontsize.";'>This is text on ANOTHER PAGE.  Imagine the I wrote something witty and profound here!</p>";
?>