PHP code is executed on the server. It doesn't get sent to your browser. The PHP code may produce HTML/javascript and other client-side code which is sent to your browser.
It is occasionally possible to see php code, but only on a poorly configured server.
Pssst! server admins and programmers! Does your system rely on include files containing PHP? Do these files have a suffix of ".php"? Or do they use suffixes like ".lib" or ".inc"?
If you use .lib / .inc / anything else for your include files, make sure that your web server is configured to treat those extensions as php sources. Otherwise, if someone requests the include file directly from their browser, the raw source will be displayed.
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