Port files from old repo

src/SUMMARY.md

@@ -1,3 +1,164 @@
-# Summary
+<!-- # For Contributors
+- [For Contributors](./paths.md)
+    - [baeldung's getting started course](./examples/baeldung.md)
+    - [Core Java Volume II](./examples/core_java_vol2.md)
+    - [dev.java](./examples/dev_java.md)
+    - [geeksforgeeks](./examples/geeksforgeeks.md)
+    - [javatpoint](./examples/javatpoint.md)
+    - [Scala Book](./examples/scala_book.md)
+    - ["The Java Programming Language" (1st or 2nd ed)](./examples/the_java_programming_language_og.md)
+    - ["The Java Tutorial" (3rd ed)](./examples/the_java_tutorial_3rd_edition.md)
+    - [The Java Tutorials, online](./examples/the_java_tutorials.md)
+    - [Tour of Scala](./examples/tour_of_scala.md)
+    - [tutorialspoint](./examples/tutorialspoint.md)
+    - [tutorialspoint paid course](./examples/tutorialspoint_paid.md)
+    - [w3schools](./examples/w3schools.md) -->
+# Getting Started
+- [Hello, World](./getting_started/hello_world.md)
+# Modern Java
+- [Prelude](./prelude.md)
+- [First Steps](./first_steps.md)
+    - [Comments](./first_steps/comments.md)
+    - [Semicolons](./first_steps/semicolon.md)
+    - [Formatting](./first_steps/formatting.md)
+    - [Challenges](./first_steps/challenges.md)
+- [Local Variables](./variables.md)
+    - [Naming](./variables/naming.md)
+    - [Reassignment](./variables/reassignment.md)
+    - [Delayed Assignment](./variables/delayed_assignment.md)
+    - [Types](./variables/types.md)
+    - [Final Variables](./variables/final_variables.md)
+    - [Inferred Types](./variables/inferred_types.md)
+    - [Challenges](./variables/challenges.md)
+- [Booleans](./boolean.md)
+    - [And](./boolean/and.md)
+    - [Or](./boolean/or.md)
+    - [Not](./boolean/not.md)
+    - [Operator Precedance](./boolean/operator_precedance.md)
+    - [Challenges](./modern/bchallenges.md)
+- [Integers](./integers.md)
+    - [Addition](./integers/addition.md)
+    - [Subtraction](./integers/subtraction.md)
+    - [Multiplication](./integers/multiplication.md)
+    - [Division](./integers/division.md)
+    - [Remainder](./integers/remainder.md)
+    - [Equality](./integers/equality.md)
+    - [Comparison](./integers/comparison.md)
+    - [Chained Comparisons](./integers/chained_comparisons.md)
+    - [Operator Precedance](./integers/operator_precedance.md)
+    - [Reassignment](./integers/reassignment.md)
+    - [Shorthands for Reassignment](./integers/shorthands_for_reassignment.md)
+    - [Limits](./integers/limits.md)
+    - [Challenges](./integers/challenges.md)
+- [Floating Point Numbers](./floating_point_numbers.md)
+    - [Limits](./floating_point_numbers/limits.md)
+    - [float and double](./numbers/float_and_double.md)
+    - [Precision]()
+    - [The "epsilon" Pattern]()
 
-- [Chapter 1](./chapter_1.md)
+
+- [Strings](./strings.md)
+    - [String Theory](./strings/string_theory.md)
+    - [Escaped Characters](./strings/escaped_characters.md)
+    - [Multiline Strings](./strings/multiline.md)
+
+- [If and Else]()
+    - [If Statement]()
+        - [Relation to Delayed Assignment]()
+    - [Integer Comparisons]()
+    - [Floating Point Number Comparisons]()
+    - [String Comparisons]()
+    - [Ternary Expression]()
+
+- [While Loop]()
+- [Arrays]()
+    - ["String\[\] args"]()
+- [For Each Loop]()
+- [Counted For Loop]()
+- [Methods]()
+    - [Arguments]()
+    - [Return Value]()
+    - [void]()
+- [String Methods]()
+    - [length]()
+- [User Defined Classes]()
+    - [Fields]()
+    - [Constructors]()
+    - [Methods]()
+
+
+- [Control Flow]()
+
+<!--
+byte, short, long
+Multiversal Equality
+-->
+
+
+<!--
+# Legacy Java
+- [Legacy Java]()
+    - [Prelude]()
+    - [Subpar]()
+        - [Short]()
+        - [Scanner]()
+        - [File]()
+        - [Swing]()
+        - [Date]()
+    - [Crusty]()
+        - [Vector]()
+        - [Hashtable]()
+    - [Already Removed]()
+        - [Applets]()
+        - [Finalization]()
+-->
+
+<!--
+# Tour of Java
+- [Tour of Java](./tour_of_java.md)
+    - [Introduction]()
+    - [Basics]()
+    - [Classes]()
+    - [Methods]()
+    - [Interfaces]()
+    - [Exceptions]()
+    - [Collections]()
+    - [Enums]()
+    - [Records]()
+    - [Generic Classes]()
+    - [Inner Classes]()
+    - [Annotations]()
+    - [Reflection]()
+--> 
+
+<!--
+- Introduction
+- Basics
+- Unified Types
+- Classes
+- Default Parameter Values
+- Named Arguments
+- Traits
+- Tuples
+- Class Composition with Mixins
+- Higher-order Functions
+- Multiple Parameter Lists
+- Case Classes
+- Pattern Matching
+- Singleton Objects
+- Regular Expression Patterns
+- Extractor Objects
+- For Comprehensions
+- Generic Classes
+- Variances
+- Upper Type Bounds
+- Lower Type Bounds
+- Abstract Type Members
+- Implicit Conversions
+- Polymorphic Methods
+- Type Inference
+- Operators
+
+- Packages and Imports
+- Top Level Definitions in Packages
+-->

src/boolean.md

@@ -0,0 +1,13 @@
+# Booleans
+
+
+A `boolean` is either `true` or `false`.
+
+
+```java
+boolean onFleek = true;
+boolean badVibes = false;
+```
+
+This is used to represent situations where there are exactly two possible states.
+

src/boolean/and.md

@@ -0,0 +1,19 @@
+# And
+
+One way multiple booleans can be combined is by using the "and" operator - `&&`.
+
+```java
+boolean funToBeAround = true;
+boolean believesInFundamentalHumanRights = true;
+boolean willAskOnDate = funToBeAround && believesInFundamentalHumanRights;
+```
+
+So in this case, I will ask someone on a date if they are fun to be around _and_
+they wholeheartedly believe in the assertions made in the [Universal Declaration of Human Rights](https://www.un.org/en/about-us/universal-declaration-of-human-rights).
+
+| funToBeAround | believesInFundamentalHumanRights | willAskOnDate |
+|---------------|----------------------------------|---------------|
+| true          | true                             | true          |
+| true          | false                            | false         |
+| false         | true                             | false         |
+| false         | false                            | false         |

src/boolean/challenges.md

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+# Challenges
+
+Remember the rules for this are
+* Try to use only the information given up to this point in this book.
+* Try not to give up until you've given it a solid attempt
+
+## Challenge 1.
+
+What will this program output when run? Write down your guess and then try running it.
+
+```java
+public class Main {
+    public static void main(String[] args) {
+        boolean a = true;
+        boolean b = false;
+        boolean c = true;
+        boolean d = false;
+
+        boolean result = a || b && c || !d;
+
+        System.out.println(result);
+    }
+}
+```
+
+## Challenge 2.
+
+What will this program output when run? Write down your guess and then try running it.
+
+```java
+public class Main {
+    public static void main(String[] args) {
+        boolean a = true;
+        boolean b = false;
+        boolean c = true;
+        boolean d = false;
+
+        boolean result = !(a || b && c || !d) || (a && b || c);
+
+        System.out.println(result);
+    }
+}
+```
+
+## Challenge 3.
+
+Say you have two boolean variables, how could you use the operators we've covered to get the "exclusive or" of the two.
+
+```java
+public class Main {
+    public static void main(String[] args) {
+        // Change these two variables to test your solution
+        boolean hasIceCream = true;
+        boolean hasCookie = false;
+
+        boolean validChoice = < YOUR CODE HERE >;
+
+        System.out.println(validChoice);
+    }
+}
+```
+
+Make sure to test all the possibilities.
+
+| hasIceCream | hasCookie | validChoice |
+|-------------|-----------|-------------|
+| true        | true      | false       |
+| true        | false     | true        |
+| false       | true      | true        |
+| false       | false     | false       |

src/boolean/not.md

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+# Not
+
+Booleans can alsobe "negated" using the "not" operator - `!`. 
+
+```java
+boolean haveOreosInHouse = true;
+boolean stuckToCalorieLimit = !haveOreos;
+```
+
+So in this case, I have stuck to my calorie limit if there are _not_ Oreos in the house.
+
+| haveOreosInHouse | stuckToCalorieLimit |
+|------------------|---------------------|
+| false            | true                |
+| true             | false               |

src/boolean/operator_precedance.md

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+# Operator Precedance
+
+The operators that work on booleans have a "precedance order." 
+
+This is defines an order of operations similar to mathematics, where multiplication and division happen before
+addition and subtraction.
+
+For booleans `!` always happens first. This is followed by `&&` and then by `||`.
+
+```java
+boolean a = true;
+boolean b = false
+boolean c = false;
+
+// just as 2 + 5 * 3 "evaluates" 5 * 3 before adding 2
+// first, !b is true
+// second, a && true is true
+// third true || c is true.
+boolean result = a && !b || c;
+```
+
+Also like mathematics, parentheses can be used to control this order.
+
+```java
+// Even though || has a lower precedance than &&, we evaluate
+// !b || c first because of the parentheses.
+boolean result = a && (!b || c);
+```

src/boolean/or.md

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+# Or
+
+Another way booleans can be combined is by using the "or" operator - `||`.
+
+```java
+boolean dogLooksNice = true;
+boolean personLooksNice = false;
+boolean willAskToPetDog = dogLooksNice || personLooksNice;
+```
+
+So in this case, I will ask to pet someone's dog if either the the dog looks nice _or_ the person
+walking the dog looks nice.
+
+| dogLooksNice | personLooksNice | willAskToPetDog |
+|--------------|-----------------|-----------------|
+| true         | true            | true            |
+| true         | false           | true            |
+| false        | true            | true            |
+| false        | false           | false           |
+
+## Exclusive vs. Inclusive
+
+It is important too note that this is not an "exclusive" OR.
+
+An exclusive OR would be something like
+a child being allowed to have ice cream _or_ a cookie, but not both.
+
+The `||` operator is an "inclusive" OR, meaning the child is allowed ice cream, a cookie, or both ice cream and the cookie.
+