PHP trying to use an a tag to link a php variable to a php script

I am trying to work on a page where after the user successfully logs in, their username which is assigned from $_SESSION to be used as a link to another PHP page.

if (isset($_SESSION['id'])) {
    print 'Welcome <a href="user.php">$_SESSION["user_name"]</a>';
} else {
    changePage("login");
}

I got it mostly working (it redirects), but I can’t seem to figure out the session variable and how to pull the variable in to be used.

Answer

If you use double quotes " you can do string interpolation and do quite cool things with curly braces {}

if (isset($_SESSION['id'])) {
    echo "Welcome <a href='user.php'>{$_SESSION["user_name"]}</a>";
} else {
    changePage("login");
}

*Note that I swap the " for ' in 'user.php'

I’ve used echo above but I believe it is the same as print, it’s the double quotes that are important.

Another option using single quotes would be concatenation which is a fancy way of saying join various bits together. In that case, I would write it as so:

print 'Welcome <a href="user.php">' . $_SESSION["user_name"] . '</a>';