<?php

// Turn on output buffering
ob_start();

// Print some output to the buffer (via php)
print 'Hello ';

// You can also `step out` of PHP
?>
<em>World</em>
<?php
// Return the buffer AND clear it
$content = ob_get_clean();

// Return our buffer and then clear it
# $content = ob_get_contents();
# $did_clear_buffer = ob_end_clean();

print($content);

#> "Hello <em>World</em>"

<?php

$i = 1;
$output = null;

while( $i <= 5 ) {
    // Each loop, creates a new output buffering `level`
    ob_start();
    print "Current nest level: ". ob_get_level() . "\n";
    $i++;
}

// We're at level 5 now
print 'Ended up at level: ' . ob_get_level() . PHP_EOL;

// Get clean will `pop` the contents of the top most level (5)
$output .= ob_get_clean();
print $output;

print 'Popped level 5, so we now start from 4' . PHP_EOL;

// We're now at level 4 (we pop'ed off 5 above)

// For each level we went up, come back down and get the buffer
while( $i > 2 ) {
    print "Current nest level: " . ob_get_level() . "\n";
    echo ob_get_clean();
    $i--;
}

Current nest level: 1
Current nest level: 2
Current nest level: 3
Current nest level: 4
Current nest level: 5
Ended up at level: 5
Popped level 5, so we now start from 4
Current nest level: 4
Current nest level: 3
Current nest level: 2
Current nest level: 1

<?php
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>

<?php
function clearAllWhiteSpace($buffer) {
    return str_replace(array("\n", "\t", ' '), '', $buffer);
}

ob_start('clearAllWhiteSpace');
?>
<h1>Lorem Ipsum</h1>

<p><strong>Pellentesque habitant morbi tristique</strong> senectus et netus et malesuada fames ac turpis egestas. <a href="#">Donec non enim</a> in turpis pulvinar facilisis.</p>

<h2>Header Level 2</h2>

<ol>
   <li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li>
   <li>Aliquam tincidunt mauris eu risus.</li>
</ol>

<?php
/* Output will be flushed and processed when script ends or call
     ob_end_flush();
*/

<h1>LoremIpsum</h1><p><strong>Pellentesquehabitantmorbitristique</strong>senectusetnetusetmalesuadafamesacturpisegestas.<ahref="#">Donecnonenim</a>inturpispulvinarfacilisis.</p><h2>HeaderLevel2</h2><ol><li>Loremipsumdolorsitamet,consectetueradipiscingelit.</li><li>Aliquamtinciduntmauriseurisus.</li></ol>

<?php
ob_start();
?>
    <html>
    <head>
        <title>Example invoice</title>
    </head>
    <body>
    <h1>Invoice #0000</h1>
    <h2>Cost: &pound;15,000</h2>
    ...
    </body>
    </html>
<?php
$html = ob_get_clean();

$handle = fopen('invoices/example-invoice.html', 'w');
fwrite($handle, $html);
fclose($handle);

/**
 * Enables output buffer streaming. Calling this function
 * immediately flushes the buffer to the client, and any
 * subsequent output will be sent directly to the client.
 */
function _stream() {
    ob_implicit_flush(true);
    ob_end_flush();
}

<?php

// Start capturing the output
ob_start();

$items = ['Home', 'Blog', 'FAQ', 'Contact'];

foreach($items as $item):

// Note we're about to step "out of PHP land"
?>
  <li><?php echo $item ?></li>
<?php
// Back in PHP land
endforeach;

// $items_lists contains all the HTML captured by the output buffer
$items_li_html = ob_get_clean();
?>

<!-- Menu 1: We can now re-use that (multiple times if required) in our HTML. -->
<ul class="header-nav">
    <?php echo $items_li_html ?>
</ul>

<!-- Menu 2 -->
<ul class="footer-nav">
    <?php echo $items_li_html ?>
</ul>

<!-- Menu 1: We can now re-use that (multiple times if required) in our HTML. -->
<ul class="header-nav">
  <li>Home</li>
  <li>Blog</li>
  <li>FAQ</li>
  <li>Contact</li>
</ul>

<!-- Menu 2 -->
<ul class="footer-nav">
  <li>Home</li>
  <li>Blog</li>
  <li>FAQ</li>
  <li>Contact</li>
</ul>

Hello!
<?php
  header("Location: somepage.php");
?>