opendir php error with variables

Question

Can someone tell me what is wrong with this code?

<?php
    $user = $fgmembersite->UserFullName();
    $handle = opendir('/users/$user/');
?>

This is the error message:

opendir(/app/$user/) [function.opendir]: failed to open dir: No such file or directory in

Answer 1

Double quotes to evaluate variables

$handle = opendir("/users/$user/");

What is the difference between single-quoted and double-quoted strings in PHP?