php constants
Conversely to variables, constants are meant for defining immutable values. Constants can be accessed for any scope within a script; however, they can only contain scalar values. Constant names, like variables, are case-sensitive; they also follow the same naming requirements, with the exception of the leading $. It is considered best practice to define constants using only upper-case names.
Conversely to variables, constants are meant for defining immutable values. Constants can be accessed for any scope within a script; however, they can only contain scalar values. Constant names, like variables, are case-sensitive; they also follow the same naming requirements, with the exception of the leading $. It is considered best practice to define constants using only upper-case names.
