How to pass a PHP variable using the URL

In your link.php your echo statement must be like this:

echo '<a href="pass.php?link=' . $a . '>Link 1</a>';
echo '<a href="pass.php?link=' . $b . '">Link 2</a>';

Then in your pass.php you cannot use $a because it was not initialized with your intended string value.

You can directly compare it to a string like this:

if($_GET['link'] == 'Link1')

Another way is to initialize the variable first to the same thing you did with link.php. And, a much better way is to include the $a and $b variables in a single PHP file, then include that in all pages where you are going to use those variables as Tim Cooper mention on his post. You can also include this in a session.

All the above answers are correct, but I noticed something very important. Leaving a space between the variable and the equal sign might result in a problem. For example, (?variablename =value)

You're passing link=$a and link=$b in the hrefs for A and B, respectively. They are treated as strings, not variables. The following should fix that for you:

echo '<a href="pass.php?link=' . $a . '">Link 1</a>';

// and

echo '<a href="pass.php?link=' . $b . '">Link 2</a>';

The value of $a also isn't included on pass.php. I would suggest making a common variable file and include it on all necessary pages.

I found this solution in "Super useful bits of PHP, Form and JavaScript code" at Skytopia.

Inside "page1.php" or "page1.html":

// Send the variables myNumber=1 and myFruit="orange" to the new PHP page...
<a href="page2c.php?myNumber=1&myFruit=orange">Send variables via URL!</a> 

    //or as I needed it.
    <a href='page2c.php?myNumber={$row[0]}&myFruit={$row[1]}'>Send variables</a>

Inside "page2c.php":

<?php
    // Retrieve the URL variables (using PHP).
    $num = $_GET['myNumber'];
    $fruit = $_GET['myFruit'];
    echo "Number: ".$num."  Fruit: ".$fruit;
?>