Essential Books

Running output buffer before any content

suggest change 
ob_start();

$user_count = 0;
foreach( $users as $user ) {
    if( $user['access'] != 7 ) { continue; }
    ?>
    <li class="users user-<?php echo $user['id']; ?>">
        <a href="<?php echo $user['link']; ?>">
            <?php echo $user['name'] ?>
        </a>
    </li>
<?php
    $user_count++;
}
$users_html = ob_get_clean();

if( !$user_count ) {
    header('Location: /404.php');
    exit();
}
?>
<html>
<head>
    <title>Level 7 user results (<?php echo $user_count; ?>)</title>
</head>

<body>
<h2>We have a total of <?php echo $user_count; ?> users with access level 7</h2>
<ul class="user-list">
    <?php echo $users_html; ?>
</ul>
</body>
</html>

In this example we assume $users to be a multidimensional array, and we loop through it to find all users with an access level of 7.

If there are no results, we redirect to an error page.

We are using the output buffer here because we are triggering a header() redirect based on the result of the loop

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Output buffering:
* Output Buffering
* Basic usage getting content between buffers and clearing
* Nested output buffers
* Running output buffer before any content
* Processing the buffer via a callback
* Using Output buffer to store contents in a file useful for reports invoices etc
* Stream output to client
* Capturing the output buffer to re-use later
* Typical usage and reasons for using ob start
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39 Contributing to PHP Manual
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107 How to break down an URL
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109 Contributors