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1.2 KiB
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Lecture for March 29th
Enumerated Types
These represent a fixed set of constants and include all possible values within them.
Let's look at coins. On a daily basis in the US, we use the following coins:
- Penny
- Nickel
- Dime
- Quarter
Other examples include the days of the week, clothes sizes, etc.
Enum Syntax
Let's define an enum
type
public enum Coin { PENNY, NICKEL, DIME, QUARTER}
Now declare and initialize a variable
Coin myCoin = Coin.PENNY
Arrays vs ArrayList
Arrays require you to say upfront, how many slots you need. ArrayLists are more flexible since you can change the length of the array during Runtime.
Arrays can store objects and primitives such as int
, char
, boolean
, etc.
ArrayLists can only store objects.
How to declare an ArrayList
ArrayList<objectType> list = new ArrayList<objectType>();
Differences between getting the length of the array
Array
int length = array.length;
ArrayList
int length = array.size();
For Each Loop
This is a special loop in where you tell it to go through all the elements of the array, without specifying an index.
for (String b : buildings) {
System.out.print(b);
}