使用位置标头重定向到页面？

Question

I have a function that is being run in a php file when a button is clicked on the users profile page. Once the function is complete I want the user to be redirected back to their profile page. Normally I know how to redirect but this requires including the user id to go to their specific profile. I have made the following piece of code and am attaching err=1 at the end of it in hope to try and get a message displayed in their profile.

Hope this makes sense.

<?php
    header('Location: http://localhost/ptb1/profile.php?id=echo $_SESSION['user_id']err=1');
?>

Answer 1

Read about string concatenation :

<?php
session_start();
header('Location: http://localhost/ptb1/profile.php?id=' . $_SESSION['user_id'] . '&err=1');

You also need to call session_start() before you try and use $_SESSION variables.