A constant is an identifier (name) for a value that cannot change during the execution of the program.
A valid constant name starts with a letter or underscore, followed by any number of letters, numbers, or underscores.
Constants are case-sensitive and have only a single scope, just like variables.
By convention, constant identifiers are always uppercase.
Constants can be declared by prepending the const keyword to a variable declaration.
const any foo = 12;
Modifying a constant during runtime will result in an error being thrown.
const any PI = 3.14159;
PI = 1; # Error