PHP - What are constants, are they good practice, and how do they differ from variables?

Question

Beginner question...

How different is define("$a",365); from $a = 365;?

Thanks!

JDelage

Answer 1

If you define constant define("YEAR",365); you can't change it during execution time so YEAR will always be 365 no meter what. On the other hand variables can change their value during script execution also they have local scope, which means they are available just in the function file they are declared. Constants have global scope they can be accessed from all over the script.

http://php.net/manual/en/language.constants.php

http://planetozh.com/blog/2006/06/php-variables-vs-constants/