PHP implements 301 permanent redirection

This article introduces how PHP implements 301 permanent redirection to direct a domain name without www to a domain name with www, the implementation method is as follows: when your site domain name changes or the webpage address changes (the webpage storage directory or the webpage file name changes), how to ensure that the site

This article introduces how PHP implements 301 permanent redirection to direct a domain name without www to a domain name with www.

When your site domain name changes or the webpage address changes (the webpage storage directory or the webpage file name changes), how can you ensure that the site's traffic from search engines will not be lost during the transition period, can I update the webpage address in the search engine results? 301 redirection is an ideal solution to this problem. it can direct users and search engines to the correct webpage.

The instance code is as follows: