How can the issue of headers already being sent be resolved when trying to set a cookie in PHP?

When trying to set a cookie in PHP, the issue of "headers already sent" can be resolved by ensuring that no output is sent to the browser before calling the `setcookie()` function. This error occurs when PHP tries to set a cookie after outputting content to the browser, which includes any whitespace, HTML, or even error messages. To prevent this issue, make sure to set cookies before any output is sent, such as at the beginning of the script or using output buffering. 

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

// Set the cookie before any output
setcookie('cookie_name', 'cookie_value', time() + 3600, '/');

ob_end_flush(); // Flush output buffer
?>

Keywords

headers_sent ob_start setcookie output buffering PHP

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