Variables (continued)

Instead, a variable's scope is determined by its name:

• Local variables and Method names

  • Start with a lowercase letter or an underscore

  • i, j, first_name, _line, push, pop

• Global variables

  • Start with a dollar sign

  • $debug, $stdout, $CUSTOMER, $_

• Instance variables

  • Start with one @ sign

  • @first_name, @city, @state

• Class variables

  • Start with two @ signs

  • @@num_instances, @@TOTAL

• Constants and Class Names

  • Start with an uppercase letter

  • PI, E, MyClass, Array, String