How can PHP code be restructured to ensure that no output is sent before session_start() or header() functions?

To ensure that no output is sent before session_start() or header() functions in PHP, it is important to make sure that there is no whitespace or HTML content before these functions are called. This can be achieved by placing the session_start() function at the beginning of the PHP script, before any HTML or whitespace, and using output buffering to prevent any output from being sent before the header() function is called. 

<?php
ob_start(); // Start output buffering

session_start(); // Start the session

header("Location: newpage.php"); // Redirect to a new page

ob_end_flush(); // Flush the output buffer and send output to the browser
?>

Keywords

PHP session_start() header() output buffering ob_start()

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