Can the two codes be run together?

Question

The first part of this video tutorial is html code, and a php code is added at the end. After I input the new html text, the php part did not run. What happened?

Answer 1

Your php code must meet the requirements of php, such as <?php echo 'Hello World'; ?> This way it can be run if added to html

Answer 2

Brother, 666

Answer 3

If you want to run php code, the suffix must be .php. Other text formats cannot parse php. Common sense brother, you cannot make this kind of mistake