enum

enum type

• Fixed set of constants
• Constants should be all in capital letters (also make sure you are using final static for other constant types)
• Java enum constants are static and final implicitly
• Name it as a class name (proper case)

Use:

enum Season { WINTER, SPRING, SUMMER, FALL } 

Use .values() method to iterate over values

enum use

for (Season s : Season.values()) {
            System.out.println(s);
        }

enum use

use Enum.VALUE to set a specific value

public class SimpleExample {

    private enum Season { WINTER, SPRING, SUMMER, FALL };
    
    public static void main(String[] args) {
        Season mySeason = Season.FALL;
    }

}

switch use

You can replace multiple if else statements with switch case statements

switch(expression) {
  case x:
    // code block
  case y:
    // code block
  default:
    // code block
}

switch use

• The switch expression is evaluated once
• The value of the expression is compared with the values of each case
• If there is a match, the associated block of code is executed.
• default is optional

switch use

Remove break – what’s the behavior change?

    Season mySeason = Season.FALL;
        
        switch (mySeason) {
        case WINTER:
            System.out.println("Winter is cold");
            break;
        case FALL:
            System.out.println("Fall is supposed to be perfect weather");
            break;
        case SUMMER:
            System.out.println("School is out");
            break;
        case SPRING:
            System.out.println("Allergy season");
        }

Putting it all together

Based on the UML class diagram below and the program behavior, implement all classes

Application behavior

public class MyMediaLibrary {

    public static void main(String[] args) {
        MediaLibrary myMediaLibrary = new MediaLibrary();
        myMediaLibrary.addMedia(new Movie("The Alien", Media.Genre.SCIFI));
        myMediaLibrary.addMedia(new TVShow("The X-Files", Media.Genre.SCIFI));
        myMediaLibrary.addMedia(new TVShow("Seinfield", Media.Genre.COMEDY));
        System.out.println(myMediaLibrary.toString());  
    }

}

Movie title: The Alien
Show title: The X-Files
Show title: Seinfield