Are there any best practices or guidelines to follow when setting cookies in PHP to avoid header modification errors?

When setting cookies in PHP, it's important to ensure that no output (including whitespace) is sent to the browser before setting the cookie headers. This is because PHP headers must be set before any content is sent to the browser. To avoid header modification errors, it's best practice to use the `header()` function to set cookies before any other output. 

<?php
// Make sure no output is sent before setting cookies
ob_start();

// Set cookies using header() function
header('Set-Cookie: cookie_name=cookie_value; expires=expires; path=/');

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

Keywords

cookies PHP header modification errors guidelines best practices

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