Question

The first one is enum class

enum coffeeSize{
    BIG(8), HUGE(10), OVERWHELMING(16);
    private int ounces;
    coffeeSize(int ounces ){
        this.ounces = ounces;
    }
    public int getOunces(){
        return ounces;
    }

}

This is class CoffeeTest1 and main

 public class CoffeeTest1 {
      coffeeSize size;

      public static void main (String args[]) {
          CoffeeTest1 drink1 = new CoffeeTest1();
          drink1.size = coffeeSize.BIG;

          System.out.println(" " + drink1.size.getOunces());
      }
}

The below is output

8  

My question :
I don’t understand the how drink1.size.getounces() manage to output 8. I haven’t given constructor coffeeSize(8) object (ex: coffeeSize somex = new coffeeSize(BIG)). I want to know this simple subtle logic behind. Can someone help me understand please?

Answer 1

I dont understand the how “drink1.size.getounces() ” manage to output 8.

[…]

I want to know this simple subtle logic behind.

To understand the logic behind this, you can think of your enum as a regular class (which is actually how it is compiled), and

BIG(8)

as an instance of this class similar to

new coffeesize(8);

It should now be clear why drink1.size.getOunces() prints 8: BIG is just an instance of the coffeesize enum, for which you set ounces to 8 when constructing it.