I just bought a brand new macbook pro, and installed MAMP on it. All the files are saved in the right location /htdocs and the first time I ran my PHP files, everything was working fine. Then when I changed the script and ran it again, the browser wouldn't reload the page, it would display the old (cached?) version of the file.
I tried doing a hard refresh, a browser restart, a different browser, a server restart but none of that seems to work.
The same thing was happening to me a few months ago. Here's the solution that worked for me: Go to preferences in MAMP, and change the Apache Port to 80, and the MYSQL port to 3306, then restart the server and try loading your PHP.