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Assesment 2 Study Guide.md

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+FUNDAMENTALS
+  Classes
+    - Template for an object
+    - Core Java Chapter 4.2/4.3
+  Objects
+    - State/Instance/Signature
+    - Core Java Chapter 4.6
+  Packages
+    - A package is a namespace that organizes a set of related classes and
+    interfaces. Conceptually you can think of packages as being similar to
+    different folders on your computer
+    - Core Java Chapter 4.7
+  Operators
+    - manipulates variables
+    - https://www.tutorialspoint.com/java/java_basic_operators.htm
+    - Core Java Chapter 3.5
+  Variables
+    - http://www.learnjavaonline.org/en/Variables_and_Types
+    - Core Java Chapter 3.4
+
+
+CONTROL FLOW (Core Java Chapter 3.8)
+  If (Core Java Chapter 3.8.2)
+    If-Else
+    - EXAMPLE
+      if(something that is true/false){then do this}
+      else if(the thing above never happened, maybe this happens??) {then do this}
+      else {none of that happened so do this....}
+  While (Core Java Chapter 3.8.3)
+    -EXAMPLE
+      while(something is true/false){keep doing this}
+      ** while loops only run if the conditional they are dependent on are a truthy
+         statement
+    Do While
+      -EXAMPLE
+        do{this thing}while(something is true/false)
+      ** Do While loops always run at least once because they do not access
+      the truthiness of the condition until it has already done the loop once.
+  For (Core Java Chapter 3.8.4)
+    - EXAMPLE
+            start               until                     do this to the counter
+      for(int i = 0; i < or > or = or <= or >= something; increment i in someway)
+      {do this thing until the loop conditions are met}
+      ** for loops will iterate over a code block until the counter is outside
+      the parameters of the loop
+    ForEach
+    -EXAMPLE
+      for (Element e: c)
+      {System.out.print(e)}
+      ** for each element "e" in "c" (array, arrayList, some other collection)
+         do this code block
+
+      ForEach With Iterables
+      -EXAMPLE
+      for (Iterator i = c.iterator(); i.hasNext();)
+      {System.out.print(i.next())}
+      ** accesses elements of a collection one by one until there are no more to
+        be found.  On each element in the collection a block of code is executed
+      Ternary Statements
+      - https://alvinalexander.com/java/edu/pj/pj010018
+      - Core Java pages 62/63
+      -EXAMPLE
+        condition ? expression1 : expression2
+      ** if some condition is met, do expression1, if the condiditon is not met
+         do condition2
+
+
+ARRAYS (Core Java Chapter 3.10 pages 108 to 124)
+  allocate arrays
+    - https://www.geeksforgeeks.org/arrays-in-java/
+  copy arrays
+    - since arrays are objects in java they are "cloneable" and because of this
+    you can create copies of an array.
+
+    There are many ways to copy array in java. Let’s look at them one by one.
+
+    1.) Object.clone(): Object class provides clone() method and since array in
+    java is also an Object, you can use this method to achieve full array copy.
+    This method will not suit you if you want partial copy of the array.
+    2.) System.arraycopy(): System class arraycopy() is the best way to do partial
+    copy of an array. It provides you an easy way to specify the total number of
+    elements to copy and the source and destination array index positions.
+    For example System.arraycopy(source, 3, destination, 2, 5) will copy
+    5 elements from source to destination, beginning from 3rd index of source to
+    2nd index of destination.
+    3.) Arrays.copyOf(): If you want to copy first few elements of an array or
+    full copy of array, you can use this method. Obviously it’s not versatile
+    like System.arraycopy() but it’s also not confusing and easy to use.
+    This method internally use System arraycopy() method.
+    4.) Arrays.copyOfRange(): If you want few elements of an array to be copied,
+    where starting index is not 0, you can use this method to copy partial array.
+    Again this method is also using System arraycopy method itself.
+
+
+COLLECTIONS
+  arrayLists (Core Java Chapter 5.3 pages 244 to 247)
+    - https://www.geeksforgeeks.org/arraylist-in-java/
+  hashMaps (Core Java page 504)
+    -https://beginnersbook.com/2013/12/hashmap-in-java-with-example/
+  treeMaps (Core Java page 497)
+    -http://www.baeldung.com/java-treemap
+
+    ** Whats the difference between a hashMap and a treeMap?!
+       hashMaps are great if you need to store things with an associated key value,
+       but don't care how they are sorted (if you know all the keys you can easily get
+       access to those values).  TreeMaps are sorted lists, that means that all of
+       the key values are sorted in some logical way, are your key values numbers?
+       Guess what, that tree map has them in numerical order.  Are your keys words?
+       BAM! The treeMap sorts those keys alphabetically.  Magic.  
+
+INTERFACES VS ABSTRACT CLASSES
+  Abstract Classes (Core Java page 221 to 227)
+    - https://www.geeksforgeeks.org/abstract-classes-in-java/
+  Interfaces (Core Java page 297)
+    - https://www.tutorialspoint.com/java/java_interfaces.htm
+  Abstract Classes VS Interfaces
+    -https://www.geeksforgeeks.org/difference-between-abstract-class-and-interface-in-java/
+    ** Abstract classes and Interfaces seemingly do the same thing. So why have multiple
+    ways to do the same thing?  It comes down to flexibility.
+
+    When to use what?
+
+    Consider using abstract classes if any of these statements apply to your situation:
+
+    In java application, there are some related classes that need to share some
+    lines of code then you can put these lines of code within abstract class and
+    this abstract class should be extended by all these related classes.
+
+    You can define non-static or non-final field(s) in abstract class, so that
+    via a method you can access and modify the state of Object to which they belong.
+
+    You can expect that the classes that extend an abstract class have many common
+    methods or fields, or require access modifiers other than public (such as protected
+    and private).
+
+    Consider using interfaces if any of these statements apply to your situation:
+
+    It is total abstraction, All methods declared within an interface must be implemented
+    by the class(es) that implements this interface.
+    A class can implement more than one interface. It is called multiple inheritance.
+    You want to specify the behavior of a particular data type, but not concerned
+    about who implements its behavior.
+
+  extend vs implements
+    - classes extend other classes/abstract classes
+    - classes implement interfaces
+  override methods
+  -https://www.geeksforgeeks.org/overriding-in-java/
+  final
+  -https://en.wikipedia.org/wiki/Final_(Java)
+    methods
+      - A final method cannot be overridden or hidden by subclasses
+    classes
+      - A final class cannot be subclassed
+    variables
+      - A final variable can only be initialized once
+
+ENUMS
+- Core Java pages 65, 258
+- https://dzone.com/articles/using-java-enums
+
+**In applications, you often need to work with a set of constant values.
+For example, representing a contract status with the “permanent”, “temp”, and
+“intern” values, or directions with the “north”, “south”, “east”, and “west” values.
+
+In Java, you use the enum type (short for enumeration), a special datatype
+created to represent such lists of predefined constants.
+
+GENERICS
+-https://www.geeksforgeeks.org/generics-in-java/
+
+LAMBDA
+-Core Java Chapter 6.3 pages 314 to 328
+-http://tutorials.jenkov.com/java/lambda-expressions.html
+-https://www.geeksforgeeks.org/lambda-expressions-java-8/
+**Lambda expressions basically express instances of functional interfaces
+(An interface with single abstract method is called functional interface.
+An example is java.lang.Runnable). lambda expressions implement the only abstract
+function and therefore implement functional interfaces
+
+lambda expressions are added in Java 8 and provide below functionalities.
+
+Enable to treat functionality as a method argument, or code as data.
+A function that can be created without belonging to any class.
+A lambda expression can be passed around as if it was an object and executed on demand.
+
+MYSQL
+-Dolio's Slides
+-https://www.digitalocean.com/community/tutorials/a-basic-mysql-tutorial
+-https://www.w3schools.com/sql/sql_quickref.asp
+
+ERRORS AND EXCEPTIONS (Core Java Chapter 7)
+-https://www.tutorialspoint.com/java/java_exceptions.htm
+  Exceptions checked VS unchecked (Core Java Chapter 7.1 pages 358 to 365)
+  TRY/CATCH/FINALLY (Core Java 7.2 pages 367 to 377)
+  Logging (Core Java Chapter 7.5 pages 389 to 399)
+    Logging Levels (Core Java Chapter 7.5.2 page 390)
+
+PARSING
+-https://www.quora.com/What-does-parsing-mean-in-Java
+** fairly common parse method in Java is the parseInt() method in the Integer class.
+   This method takes a string as a parameter and looks at the string to find anything
+   that can be represented as an integer inside that string.
+   - EXAMPLE
+   Integer numbers = Integer.parseInt("123");
+   (return 123)

Learn X in Y minutes: JAVA.md

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+
+COMMENTING
+// Single-line comments start with //
+
+/*
+Multi-line comments look like this.
+*/
+
+/**
+ * JavaDoc comments look like this. Used to describe the Class or various
+ * attributes of a Class.
+ * Main attributes:
+ *
+ * @author         Name (and contact information such as email) of author(s).
+ * @version     Current version of the program.
+ * @since        When this part of the program was first added.
+ * @param         For describing the different parameters for a method.
+ * @return        For describing what the method returns.
+ * @deprecated  For showing the code is outdated or shouldn't be used.
+ * @see         Links to another part of documentation.
+*/
+
+IMPORTING THING INTO YOUR PROGRAM
+          // Import ArrayList class inside of the java.util package
+          import java.util.ArrayList;
+          // Import all classes inside of java.security package
+          import java.security.*;
+
+*** if you know that something your using exists already somewhere else in your
+program OR in a package that has already been imported you can have IntelliJ
+auto-import it for you!  Simple click on the thing that needs to be imported
+and then hold OPTION and hit ENTER.
+
+TYPES (CORE JAVA CHAPTER 3.3 pages 47 to 52)
+-There are many types of data in Java, most are classes and have built in methods
+that can be used on things of that type, these are known as "reference" types.  
+Want to know what you can do?  Check the api of that class.
+
+-There are 8 "primitive" types of data that are not classes and have not built
+in methods. They are: boolean(true/false), character, byte, short, integer(int),
+long, float, doable.
+
+DECLARING VARIABLES (CORE JAVA CHAPTER 3.4 pages 53 to 54)
+        // Initialize a variable using <type> <name> = <val>
+        int barInt = 1;
+        // Initialize multiple variables of same type with same
+        // value <type> <name1>, <name2>, <name3>
+        // <name1> = <name2> = <name3> = <val>
+        int barInt1, barInt2, barInt3;
+        barInt1 = barInt2 = barInt3 = 1;
+
+VARIABLES TYPES
+
+        // Byte - 8-bit signed two's complement integer
+        // (-128 <= byte <= 127)
+        byte fooByte = 100;
+
+        // If you would like to interpret a byte as an unsigned integer
+        // then this simple operation can help
+        int unsignedIntLessThan256 = 0xff & fooByte;
+        // this contrasts a cast which can be negative.
+        int signedInt = (int) fooByte;
+
+        // Short - 16-bit signed two's complement integer
+        // (-32,768 <= short <= 32,767)
+        short fooShort = 10000;
+
+        // Integer - 32-bit signed two's complement integer
+        // (-2,147,483,648 <= int <= 2,147,483,647)
+        int bazInt = 1;
+
+        // Long - 64-bit signed two's complement integer
+        // (-9,223,372,036,854,775,808 <= long <= 9,223,372,036,854,775,807)
+        long fooLong = 100000L;
+        // L is used to denote that this variable value is of type Long;
+        // anything without is treated as integer by default.
+
+        // Note: byte, short, int and long are signed. They can have positive and negative values.
+        // There are no unsigned variants.
+        // char, however, is 16-bit unsigned.
+
+        // Float - Single-precision 32-bit IEEE 754 Floating Point
+        // 2^-149 <= float <= (2-2^-23) * 2^127
+        float fooFloat = 234.5f;
+        // f or F is used to denote that this variable value is of type float;
+        // otherwise it is treated as double.
+
+        // Double - Double-precision 64-bit IEEE 754 Floating Point
+        // 2^-1074 <= x <= (2-2^-52) * 2^1023
+        double fooDouble = 123.4;
+
+        // Boolean - true & false
+        boolean fooBoolean = true;
+        boolean barBoolean = false;
+
+        // Char - A single 16-bit Unicode character
+        char fooChar = 'A';
+
+        // final variables can't be reassigned,
+        final int HOURS_I_WORK_PER_WEEK = 9001;
+        // but they can be initialized later.
+        final double E;
+        E = 2.71828;
+
+       // Other data types worth checking out
+       // ArrayLists - Like arrays except more functionality is offered, and
+       //              the size is mutable.
+       // LinkedLists - Implementation of doubly-linked list. All of the
+       //               operations perform as could be expected for a
+       //               doubly-linked list.
+       // Maps - A mapping of key Objects to value Objects. Map is
+       //        an interface and therefore cannot be instantiated.
+       //        The type of keys and values contained in a Map must
+       //        be specified upon instantiation of the implementing
+       //        class. Each key may map to only one corresponding value,
+       //        and each key may appear only once (no duplicates).
+       // HashMaps - This class uses a hashtable to implement the Map
+       //            interface. This allows the execution time of basic
+       //            operations, such as get and insert element, to remain
+       //            constant-amortized even for large sets.
+       // TreeMap - A Map that is sorted by its keys. Each modification
+       //           maintains the sorting defined by either a Comparator
+       //           supplied at instantiation, or comparisons of each Object
+       //           if they implement the Comparable interface.
+       //           Failure of keys to implement Comparable combined with failure to
+       //           supply a Comparator will throw ClassCastExceptions.
+       //           Insertion and removal operations take O(log(n)) time
+       //           so avoid using this data structure unless you are taking
+       //           advantage of the sorting.
+
+
+OPERATORS (CORE JAVA CHAPTER 3.5 pages 56 to 65)
+
+        System.out.println("\n->Operators");
+
+        int i1 = 1, i2 = 2; // Shorthand for multiple declarations
+
+        // Arithmetic is straightforward
+        System.out.println("1+2 = " + (i1 + i2)); // => 3
+        System.out.println("2-1 = " + (i2 - i1)); // => 1
+        System.out.println("2*1 = " + (i2 * i1)); // => 2
+        System.out.println("1/2 = " + (i1 / i2)); // => 0 (int/int returns int)
+        System.out.println("1/2.0 = " + (i1 / (double)i2)); // => 0.5
+
+        // Modulo
+        System.out.println("11%3 = "+(11 % 3)); // => 2
+
+        // Comparison operators
+        System.out.println("3 == 2? " + (3 == 2)); // => false
+        System.out.println("3 != 2? " + (3 != 2)); // => true
+        System.out.println("3 > 2? " + (3 > 2)); // => true
+        System.out.println("3 < 2? " + (3 < 2)); // => false
+        System.out.println("2 <= 2? " + (2 <= 2)); // => true
+        System.out.println("2 >= 2? " + (2 >= 2)); // => true
+
+        // Boolean operators
+        System.out.println("3 > 2 && 2 > 3? " + ((3 > 2) && (2 > 3))); // => false
+        System.out.println("3 > 2 || 2 > 3? " + ((3 > 2) || (2 > 3))); // => true
+        System.out.println("!(3 == 2)? " + (!(3 == 2))); // => true
+
+        // Bitwise operators!
+        /*
+        ~      Unary bitwise complement
+        <<     Signed left shift
+        >>     Signed/Arithmetic right shift
+        >>>    Unsigned/Logical right shift
+        &      Bitwise AND
+        ^      Bitwise exclusive OR
+        |      Bitwise inclusive OR
+        */
+
+        // Increment operators
+        int i = 0;
+        System.out.println("\n->Inc/Dec-rementation");
+        // The ++ and -- operators increment and decrement by 1 respectively.
+        // If they are placed before the variable, they increment then return;
+        // after the variable they return then increment.
+        System.out.println(i++); // i = 1, prints 0 (post-increment)
+        System.out.println(++i); // i = 2, prints 2 (pre-increment)
+        System.out.println(i--); // i = 1, prints 2 (post-decrement)
+        System.out.println(--i); // i = 0, prints 0 (pre-decrement)  
+
+
+ENUMS (CORE JAVA CHAPTER 3.5.9 page 65)
+
+// An enum type is a special data type that enables for a variable to be a set
+// of predefined constants. The variable must be equal to one of the values
+// that have been predefined for it. Because they are constants, the names of
+// an enum type's fields are in uppercase letters. In the Java programming
+// language, you define an enum type by using the enum keyword. For example,
+// you would specify a days-of-the-week enum type as:
+public enum Day {
+    SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
+    THURSDAY, FRIDAY, SATURDAY
+}
+
+// We can use our enum Day like that:
+public class EnumTest {
+    // Variable Enum
+    Day day;
+
+    public EnumTest(Day day) {
+        this.day = day;
+    }
+
+    public void tellItLikeItIs() {
+        switch (day) {
+            case MONDAY:
+                System.out.println("Mondays are bad.");
+                break;
+            case FRIDAY:
+                System.out.println("Fridays are better.");
+                break;
+            case SATURDAY:
+            case SUNDAY:
+                System.out.println("Weekends are best.");
+                break;
+            default:
+                System.out.println("Midweek days are so-so.");
+                break;
+        }
+    }
+
+    public static void main(String[] args) {
+        EnumTest firstDay = new EnumTest(Day.MONDAY);
+        firstDay.tellItLikeItIs(); // => Mondays are bad.
+        EnumTest thirdDay = new EnumTest(Day.WEDNESDAY);
+        thirdDay.tellItLikeItIs(); // => Midweek days are so-so.
+    }
+}
+
+// Enum types are much more powerful than we show above.
+// The enum body can include methods and other fields.
+// You can see more at https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html
+
+
+
+STRINGS (CORE JAVA CHAPTER 3.6 pages 65 to 77)
+
+// Strings
+String fooString = "My String Is Here!";
+
+// \n is an escaped character that starts a new line
+String barString = "Printing on a new line?\nNo Problem!";
+// \t is an escaped character that adds a tab character
+String bazString = "Do you want to add a tab?\tNo Problem!";
+System.out.println(fooString);
+System.out.println(barString);
+System.out.println(bazString);
+
+// String Building
+// #1 - with plus operator
+// That's the basic way to do it (optimized under the hood)
+String plusConcatenated = "Strings can " + "be concatenated " + "via + operator.";
+System.out.println(plusConcatenated);
+// Output: Strings can be concatenated via + operator.
+
+// #2 - with StringBuilder
+// This way doesn't create any intermediate strings. It just stores the string pieces, and ties them together
+// when toString() is called.
+// Hint: This class is not thread safe. A thread-safe alternative (with some impact on performance) is StringBuffer.
+StringBuilder builderConcatenated = new StringBuilder();
+builderConcatenated.append("You ");
+builderConcatenated.append("can use ");
+builderConcatenated.append("the StringBuilder class.");
+System.out.println(builderConcatenated.toString()); // only now is the string built
+// Output: You can use the StringBuilder class.
+
+// StringBuilder is efficient when the fully constructed String is not required until the end of some processing.
+StringBuilder stringBuilder = new StringBuilder();
+String inefficientString = "";
+for (int i = 0 ; i < 10; i++) {
+   stringBuilder.append(i).append(" ");
+   inefficientString += i + " ";
+}
+System.out.println(inefficientString);
+System.out.println(stringBuilder.toString());
+// inefficientString requires a lot more work to produce, as it generates a String on every loop iteration.
+// Simple concatenation with + is compiled to a StringBuilder and toString()
+// Avoid string concatenation in loops.
+
+// #3 - with String formatter
+// Another alternative way to create strings. Fast and readable.
+String.format("%s may prefer %s.", "Or you", "String.format()");
+// Output: Or you may prefer String.format().
+
+
+BIG NUMBERS (CORE JAVA CHAPTER 3.9 page 108)
+
+// BigInteger - Immutable arbitrary-precision integers
+//
+// BigInteger is a data type that allows programmers to manipulate
+// integers longer than 64-bits. Integers are stored as an array of
+// of bytes and are manipulated using functions built into BigInteger
+//
+// BigInteger can be initialized using an array of bytes or a string.
+BigInteger fooBigInteger = new BigInteger(fooByteArray);
+
+// BigDecimal - Immutable, arbitrary-precision signed decimal number
+//
+// A BigDecimal takes two parts: an arbitrary precision integer
+// unscaled value and a 32-bit integer scale
+//
+// BigDecimal allows the programmer complete control over decimal
+// rounding. It is recommended to use BigDecimal with currency values
+// and where exact decimal precision is required.
+//
+// BigDecimal can be initialized with an int, long, double or String
+// or by initializing the unscaled value (BigInteger) and scale (int).
+BigDecimal fooBigDecimal = new BigDecimal(fooBigInteger, fooInt);
+
+// Be wary of the constructor that takes a float or double as
+// the inaccuracy of the float/double will be copied in BigDecimal.
+// Prefer the String constructor when you need an exact value.
+BigDecimal tenCents = new BigDecimal("0.1");     
+
+
+
+ARRAYS (CORE JAVA CHAPTER 3.10 pages 111 to 124)
+// The array size must be decided upon instantiation
+// The following formats work for declaring an array
+// <datatype>[] <var name> = new <datatype>[<array size>];
+// <datatype> <var name>[] = new <datatype>[<array size>];
+int[] intArray = new int[10];
+String[] stringArray = new String[1];
+boolean boolArray[] = new boolean[100];
+
+// Another way to declare & initialize an array
+int[] y = {9000, 1000, 1337};
+String names[] = {"Bob", "John", "Fred", "Juan Pedro"};
+boolean bools[] = {true, false, false};
+
+// Indexing an array - Accessing an element
+System.out.println("intArray @ 0: " + intArray[0]);
+
+// Arrays are zero-indexed and mutable.
+intArray[1] = 1;
+System.out.println("intArray @ 1: " + intArray[1]); // => 1
+
+
+
+CONTROL FLOW (CORE JAVA CHAPTER 3.8 pages 89 to 106)
+
+// If statements are c-like
+        int j = 10;
+        if (j == 10) {
+            System.out.println("I get printed");
+        } else if (j > 10) {
+            System.out.println("I don't");
+        } else {
+            System.out.println("I also don't");
+        }
+
+        // While loop
+        int fooWhile = 0;
+        while(fooWhile < 100) {
+            System.out.println(fooWhile);
+            // Increment the counter
+            // Iterated 100 times, fooWhile 0,1,2...99
+            fooWhile++;
+        }
+        System.out.println("fooWhile Value: " + fooWhile);
+
+        // Do While Loop
+        int fooDoWhile = 0;
+        do {
+            System.out.println(fooDoWhile);
+            // Increment the counter
+            // Iterated 99 times, fooDoWhile 0->99
+            fooDoWhile++;
+        } while(fooDoWhile < 100);
+        System.out.println("fooDoWhile Value: " + fooDoWhile);
+
+        // For Loop
+        // for loop structure => for(<start_statement>; <conditional>; <step>)
+        for (int fooFor = 0; fooFor < 10; fooFor++) {
+            System.out.println(fooFor);
+            // Iterated 10 times, fooFor 0->9
+        }
+        System.out.println("fooFor Value: " + fooFor);
+
+        // Nested For Loop Exit with Label
+        outer:
+        for (int i = 0; i < 10; i++) {
+          for (int j = 0; j < 10; j++) {
+            if (i == 5 && j ==5) {
+              break outer;
+              // breaks out of outer loop instead of only the inner one
+            }
+          }
+        }
+
+        // For Each Loop
+        // The for loop is also able to iterate over arrays as well as objects
+        // that implement the Iterable interface.
+        int[] fooList = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+        // for each loop structure => for (<object> : <iterable>)
+        // reads as: for each element in the iterable
+        // note: the object type must match the element type of the iterable.
+        for (int bar : fooList) {
+            System.out.println(bar);
+            //Iterates 9 times and prints 1-9 on new lines
+        }
+
+        // Switch Case
+        // A switch works with the byte, short, char, and int data types.
+        // It also works with enumerated types (discussed in Enum Types), the
+        // String class, and a few special classes that wrap primitive types:
+        // Character, Byte, Short, and Integer.
+        // Starting in Java 7 and above, we can also use the String type.
+        // Note: Do remember that, not adding "break" at end any particular case ends up in
+        // executing the very next case(given it satisfies the condition provided) as well.
+        int month = 3;
+        String monthString;
+        switch (month) {
+            case 1: monthString = "January";
+                    break;
+            case 2: monthString = "February";
+                    break;
+            case 3: monthString = "March";
+                    break;
+            default: monthString = "Some other month";
+                     break;
+        }
+        System.out.println("Switch Case Result: " + monthString);
+
+        // Conditional Shorthand (TERNARY STATEMENTS)
+        // You can use the '?' operator for quick assignments or logic forks.
+        // Reads as "If (statement) is true, use <first value>, otherwise, use
+        // <second value>"
+        int foo = 5;
+        String bar = (foo < 10) ? "A" : "B";
+        System.out.println("bar : " + bar); // Prints "bar : A", because the
+        // statement is true.
+        // Or simply
+        System.out.println("bar : " + (foo < 10 ? "A" : "B"));
+
+
+
+CLASSES (CORE JAVA 4.3 pages 145 to 157)
+
+        // Class Declaration Syntax:
+        // <public/private/protected> class <class name> {
+        //    // data fields, constructors, functions all inside.
+        //    // functions are called as methods in Java.
+        // }
+
+        class Bicycle {
+
+          // Bicycle's Fields/Variables
+          public int cadence; // Public: Can be accessed from anywhere
+          private int speed;  // Private: Only accessible from within the class
+          protected int gear; // Protected: Accessible from the class and subclasses
+          String name; // default: Only accessible from within this package
+          static String className; // Static class variable
+
+          // Static block
+          // Java has no implementation of static constructors, but
+          // has a static block that can be used to initialize class variables
+          // (static variables).
+          // This block will be called when the class is loaded.
+          static {
+          className = "Bicycle";
+            }
+
+    // Constructors are a way of creating classes
+    // This is a constructor
+        public Bicycle() {
+        // You can also call another constructor:
+        // this(1, 50, 5, "Bontrager");
+        gear = 1;
+        cadence = 50;
+        speed = 5;
+        name = "Bontrager";
+          }
+        // This is a constructor that takes arguments
+              public Bicycle(int startCadence, int startSpeed, int startGear,
+              String name) {
+              this.gear = startGear;
+              this.cadence = startCadence;
+              this.speed = startSpeed;
+              this.name = name;
+                }
+
+
+INHERITANCE (CORE JAVA CHAPTER 5.1 pages 204 to 227)
+
+// PennyFarthing is a subclass of Bicycle
+class PennyFarthing extends Bicycle {
+    // (Penny Farthings are those bicycles with the big front wheel.
+    // They have no gears.)
+
+    public PennyFarthing(int startCadence, int startSpeed) {
+        // Call the parent constructor with super
+        super(startCadence, startSpeed, 0, "PennyFarthing");
+    }
+
+    // You should mark a method you're overriding with an @annotation.
+    // To learn more about what annotations are and their purpose check this
+    // out: http://docs.oracle.com/javase/tutorial/java/annotations/
+    @Override
+    public void setGear(int gear) {
+        this.gear = 0;
+    }
+}
+
+// Object casting
+// Since the PennyFarthing class is extending the Bicycle class, we can say
+// a PennyFarthing is a Bicycle and write :
+// Bicycle bicycle = new PennyFarthing();
+// This is called object casting where an object is taken for another one. There
+// are lots of details and deals with some more intermediate concepts here:
+// https://docs.oracle.com/javase/tutorial/java/IandI/subclasses.html
+
+// Interfaces
+// Interface declaration syntax
+// <access-level> interface <interface-name> extends <super-interfaces> {
+//     // Constants
+//     // Method declarations
+// }
+
+// Example - Food:
+public interface Edible {
+    public void eat(); // Any class that implements this interface, must
+                       // implement this method.
+}
+
+public interface Digestible {
+    public void digest();
+    // Since Java 8, interfaces can have default method.
+    public default void defaultMethod() {
+        System.out.println("Hi from default method ...");
+    }
+}
+
+// We can now create a class that implements both of these interfaces.
+public class Fruit implements Edible, Digestible {
+    @Override
+    public void eat() {
+        // ...
+    }
+
+    @Override
+    public void digest() {
+        // ...
+    }
+}
+
+// In Java, you can extend only one class, but you can implement many
+// interfaces. For example:
+public class ExampleClass extends ExampleClassParent implements InterfaceOne,
+    InterfaceTwo {
+    @Override
+    public void InterfaceOneMethod() {
+    }
+
+    @Override
+    public void InterfaceTwoMethod() {
+    }
+
+}
+
+// Abstract Classes
+
+// Abstract Class declaration syntax
+// <access-level> abstract class <abstract-class-name> extends
+// <super-abstract-classes> {
+//     // Constants and variables
+//     // Method declarations
+// }
+
+// Abstract Classes cannot be instantiated.
+// Abstract classes may define abstract methods.
+// Abstract methods have no body and are marked abstract
+// Non-abstract child classes must @Override all abstract methods
+// from their super-classes.
+// Abstract classes can be useful when combining repetitive logic
+// with customised behavior, but as Abstract classes require
+// inheritance, they violate "Composition over inheritance"
+// so consider other approaches using composition.
+// https://en.wikipedia.org/wiki/Composition_over_inheritance
+
+public abstract class Animal
+{
+    private int age;
+
+    public abstract void makeSound();
+
+    // Method can have a body
+    public void eat()
+    {
+        System.out.println("I am an animal and I am Eating.");
+        // Note: We can access private variable here.
+        age = 30;
+    }
+
+    public void printAge()
+    {
+        System.out.println(age);
+    }
+
+    // Abstract classes can have main method.
+    public static void main(String[] args)
+    {
+        System.out.println("I am abstract");
+    }
+}
+
+class Dog extends Animal
+{
+    // Note still have to override the abstract methods in the
+    // abstract class.
+    @Override
+    public void makeSound()
+    {
+        System.out.println("Bark");
+        // age = 30;    ==> ERROR!    age is private to Animal
+    }
+
+    // NOTE: You will get an error if you used the
+    // @Override annotation here, since java doesn't allow
+    // overriding of static methods.
+    // What is happening here is called METHOD HIDING.
+    // Check out this SO post: http://stackoverflow.com/questions/16313649/
+    public static void main(String[] args)
+    {
+        Dog pluto = new Dog();
+        pluto.makeSound();
+        pluto.eat();
+        pluto.printAge();
+    }
+}
+
+FINAL CLASSES/METHODS (CORE JAVA CHAPTER 5.1.7 page 217)
+
+
+// Final Classes
+
+// Final Class declaration syntax
+// <access-level> final <final-class-name> {
+//     // Constants and variables
+//     // Method declarations
+// }
+
+// Final classes are classes that cannot be inherited from and are therefore a
+// final child. In a way, final classes are the opposite of abstract classes
+// because abstract classes must be extended, but final classes cannot be
+// extended.
+public final class SaberToothedCat extends Animal
+{
+    // Note still have to override the abstract methods in the
+    // abstract class.
+    @Override
+    public void makeSound()
+    {
+        System.out.println("Roar");
+    }
+}
+
+// Final Methods
+public abstract class Mammal()
+{
+    // Final Method Syntax:
+    // <access modifier> final <return type> <function name>(<args>)
+
+    // Final methods, like, final classes cannot be overridden by a child
+    // class, and are therefore the final implementation of the method.
+    public final boolean isWarmBlooded()
+    {
+        return true;
+    }
+}
+
+
+
+CATCHING EXCEPTIONS (CORE JAVA CHAPTER 7.2 pages 367 to 377)
+        // Try-with-resources (Java 7+)
+        // Try-catch-finally statements work as expected in Java but in Java 7+
+        // the try-with-resources statement is also available. Try-with-resources
+        // simplifies try-catch-finally statements by closing resources
+        // automatically.
+
+        // In order to use a try-with-resources, include an instance of a class
+        // in the try statement. The class must implement java.lang.AutoCloseable.
+        try (BufferedReader br = new BufferedReader(new FileReader("foo.txt"))) {
+            // You can attempt to do something that could throw an exception.
+            System.out.println(br.readLine());
+            // In Java 7, the resource will always be closed, even if it throws
+            // an Exception.
+        } catch (Exception ex) {
+            //The resource will be closed before the catch statement executes.
+            System.out.println("readLine() failed.");
+        }
+        // No need for a finally statement in this case, the BufferedReader is
+        // already closed. This can be used to avoid certain edge cases where
+        // a finally statement might not be called.
+        // To learn more:
+        // https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html