Help with the code

Question

Why does this code not display the result?
https://code.sololearn.com/W2DSepJKrzDJ/?ref=app

Answer 1

No all of your php codes in html file, will commented out.
The extension of the file tells the server that it should run php commands and will not deprive the result from its status as HTML. Therefore, if you don't use the php extension, the server will never know it should run the php code you have in it.

Answer 2

You can't use php codes in file with html extension (test.html)
You should run file with .php extension

Answer 3

Or you can add action in form and Posting data to another php file an you can handle your formData in php file

Answer 4

Why does it say that some variables are not defined? Doesn't php create them yourself if you mention them somewhere in the code?

Answer 5

but how do I enable this extension?