I have php version 4 running on my personal web server for development. I developed a site for a client using this version. It uses .php file extensions. Now I realise that my hosting server is using an older version with .php3 file extensions. Can I safely upgrade the hosting server to the newer version. Is it just a matter of installing the newer version over the old one. or Is it just a matter of reconfiguring the older version to read .php file extensions.
PHP4 is not 100% backwards compatible with PHP3.
I'd upgrade the older version to the newer version. Read the manual for installation instructions.
