apache - How to run php files on my computer

Question

Could anyone please tell me how to run a php file locally on my system.
Currently I am using a server to run files.
I know both php & Apache to be installed.
I need to see out put of this program, for example:

<?php 
$a=5;
$b=10;
$c=$a+$b;
print $c;
?>

Can you please tell how I can run these files of if I need anything more.

Answer 1

php have a easy way to run a light server:
first cd into php file directory, then

php -S 127.0.0.1:8000

then you can run php