How can the error "Some data has already been output to browser, can't send PDF file" be resolved in PHP?

The error "Some data has already been output to browser, can't send PDF file" occurs when there is output sent to the browser before trying to send a PDF file. To resolve this, you need to make sure that no output is sent before sending the PDF file. This can be achieved by using output buffering to capture any output before sending the PDF. 

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

// Your PHP code here

ob_end_clean(); // Clean the output buffer without sending it to the browser

// Send PDF file
header('Content-Type: application/pdf');
header('Content-Disposition: attachment; filename="example.pdf"');

// Your PDF generation code here

Keywords

output buffering ob_start ob_clean ob_end_flush PDF generation

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