abernal's blog

Enums are classes

That represents an enumeration which is like a fixed set of constants. 

• Provides type-safe checking
• Is impossible to create an invalid enum type without a compile error 

A good example for enums are

• Days of the week
• Months of the year
• The cards in a deck

Sample

public enum Day {
MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY
​}

​Usage

Objectives

• Explain why software package management systems should be used
• Understand the role of both binary and source packages
• List the main available package management systems
• Understand why two levels of utilities are needed
  • One that deals with just bare packages
  • One that deals with dependencies among packages
• Explain how creating your own package enhances the control you have over exactly what goes in software and how it is installed