Are there best practices or guidelines to follow to avoid encountering the error message "Cannot modify header information - headers already sent" in PHP?

The "Cannot modify header information - headers already sent" error in PHP occurs when there is output sent to the browser before PHP sends headers, such as session_start() or header() functions. To solve this issue, make sure there is no whitespace or output before sending headers. 

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

// Your PHP code here

ob_end_flush(); // Flush the output buffer

Keywords

header output buffering ob_start ob_end_flush error_reporting

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