Don't hardcode, use Substitution Strings

You should use Substitution Strings to store system parameters and other constants. It will give you higher degree of flexibility, portability, and more maintainable applications.

Using hardcoded parameters and constants is considered to be a bad development practice (even outside APEX), and it can cause problems, should they ever need to change. Finding all instances of the parameter in an application can be difficult and there is a risk that some instances may be overlooked. To avoid hardcoding and to make our applications more maintainable and portable, APEX provides us with some built-in Substitution Strings (some of them we reviewed in Chapter 3) and enables us to define our own twenty Substitution Strings. If twenty is not enough for you, I remind you that you can always use the Substitution String notation with application level items. As those are not limited in numbers, you should not have any problems implementing the policy of not using...