Constants

• A constant is an identifier similar to a variable but whose value can't be changed. Constants are declared using the identifier final. By convention constant names are uppercase, and words within the name are separated by underscores.
• Constants allow us to keep in one place a value that may be used at multiple places in the program. They also make a program more readable and prevent us from changing things that shouldn't be changed. For example, when we use the int constant FOUL, we don't have to worry about what integer it actually refers to, and if this integer is changed in the program at some time, it won't affect anything else in the program as long as reference is made to the constant.
• A constant is normally associated with an entire class (rather than with an instance of a class). A constant, variable, or method that is associated with an entire class is declared using the identifier static. A static variable or constant in another class (if it is public) can be accessed using the class name and the dot operator, for example, Beh.FOUL.
• Here is what the declaration of the constant FOUL in the class Beh looks like:
  public static final int FOUL = 2;

© 2004. Indiana University and Michael Gasser. www.indiana.edu/~gasser/Q530/Notes/constants.html 13 Sep 2004