Constants: final

• A final variable is a constant
• Once its value has been set, it cannot be changed
• Named constants make programs easier to read and maintain
• Convention: use all-uppercase names for constants
  

  final double QUARTER_VALUE = 0.25;
  final double DIME_VALUE = 0.1;
  final double NICKEL_VALUE = 0.05;
  final double PENNY_VALUE = 0.01;
  payment = dollars + quarters * QUARTER_VALUE + dimes * DIME_VALUE
     + nickels * NICKEL_VALUE + pennies * PENNY_VALUE;