How can the "Cannot modify header information" warning in PHP be resolved when using setcookie()?

The "Cannot modify header information" warning in PHP when using setcookie() can be resolved by ensuring that no output is sent to the browser before calling the setcookie() function. This warning occurs when PHP tries to send headers after output has already been sent, which can happen if there is whitespace or HTML content before the setcookie() function. To fix this, make sure to call setcookie() before any HTML, whitespace, or echo/print statements in your PHP code. 

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

// Your PHP code here

setcookie("cookie_name", "cookie_value", time() + 3600, "/");

ob_end_flush(); // Flush output buffer
?>

Keywords

PHP setcookie() header information warning resolve

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