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