1. Code Refresher Test #1 Topics:
Variable: int, double, boolean
Operators: Arithmetic, Assignment Logical, and Relational
Control: If, Else If, Else
Loops: For, While
Method: Parameters, Returns
Arrays: Array, ArrayList

2. Variables int, double, boolean
int: Stores whole numbers
double: Stores fractional numbers
boolean: Stores true or false values

3. Arithmetic Operators Addition: + Subtraction: - Multiplication: *
Division: /
Modulo: %
Calculates the remainder after division!

4. Assignment Operators Assignment: = Compound Assignment Operators:
Add&Assign: +=
Sub&Assign: -=
Mult&Assign: *=
Div&Assign: /=
Mod&Assign: %=

5. Postfix / Prefix Operators
Note: Also called increment/decrement
x++ Postfix add one
++x Prefix add one
y- - Postfix subtract one
- -y Prefix subtract one

6. Relational Operators Equal To: == Not Equal To: != Greater Than: >
Greater Than or Equal To: >=
Less Than: <
Less Than or Equal To: <=

7. Logical Operators AND: && OR: || NOT: !
Both expressions must be true for the result to be true!
OR: ||
Either expression must be true for the result to be true!
NOT: !
True is flipped to false, false is flipped to true

8. Control Statements if(expression) { code(); }
code() is executed if the expression is true
else if(expression) { code(); }
Tacked on to an if statement, checks expression
else { code(); }
Else means everything else, NO expression!

9. Loops
For, While
For loops are used to execute a group of statements a set number of times
for(int i = 0; i < 10; i++) { System.out.println(i); }
While loops are used to execute a group of statements as long as a condition is true
while(expression == true) { code(); }

10. Methods
Methods are groups of statements that can be called at any point in a program. You can send data to methods (parameters), and receive data from a method (return).
public static int methodName(boolean b) { code(); }
This method returns a value of type int
If you want to return nothing, use void
This method takes in one boolean parameter and names it b
Call methods by writing their name and sending them parameters

11. Arrays
Arrays are used to store a set number of elements. They are accessible via indexes.
Note: Indexes start at zero in Java.
int[] myArray = new int[10]; // stores ten integers
myArray.length; // returns the length
Use a for-loop to access each element
for(int i = 0; i < myArray.length; i++) { code(); }

12. import java.util.ArrayList; ArrayLists
ArrayLists are used to store a list of data. They are also accessible via indexes.
Note: ArrayLists start out empty with zero elements.
ArrayList<Integer> myList = new ArrayList<Integer>();
myList.add(4); // adds the number 4 to the list
myList.get(0); // gets the first element in the list
myList.remove(0); // removes the first element
myList.size(); // returns the size of the list