无法在 MAMP 和 WAMP 上执行某些 php 文件

Question

I'm sorry in advance for being a noob

So I started taking a php course the instructor told viewers to install mamp or xammp
A quick google search said Wamp is better for windows so I went along with it, the problem I faced was that the php files I created were not being executed whereas the professor's php web application worked perfectly, I did everything correctly. I created a text doc replaced txt with php extension and then wrote a simple code

<?php> echo "hello world" ?>

This was not being executed, the server kept saying unable to handle this request .

So I uninstalled wamp and installed mamp, I deleted the original files from httdocs which were a simple index.php and jpg file.. I pasted two folders, one my professor's web application and the second being my practice lab. And again it displayed the same regardless of the fact that I'm opening the file through the index directory

I don't know what's the error. Can anyone help me?
I am trying to get this run for almost 3 hours

Answer 1

As per the comments above...

Seems like it could be a 500 internal server error. Try <?php echo "Hello world"; ?> <?php echo "Hello world"; ?>

500 internal server errors are shown when your php code has fatal errors that can't be processed.

Answer 2

Your error come from opening and closing tag.

Based on PSR-1 It should be <?php and ?> but not <?php>

PHP code MUST use the long <?php?> tags or the short-echo <?=?> tags; it MUST NOT use the other tag variations.