How can PHP developers prevent the "Cannot modify header information" error when setting cookies?

The "Cannot modify header information" error in PHP occurs when there is an attempt to set a cookie after headers have already been sent to the browser. To prevent this error, PHP developers should ensure that no output is sent to the browser before setting cookies. This can be achieved by placing the setcookie() function before any HTML content or using output buffering to capture any output before sending headers. 

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

// Set cookies before any output
setcookie("cookie_name", "cookie_value", time() + 3600, "/");

ob_end_flush(); // Flush the output buffer
?>

Keywords

PHP header cookies setcookie error

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