New Beginner and Advanced Practice and Solutions

.gitignore

@@ -3,4 +3,5 @@
 
 # ignore files
 c4t-java.iml
-.DS_Store
+.DS_Store
+

src/com/codefortomorrow/advanced/chapter16/practice/LinkedList.java

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+package com.codefortomorrow.advanced.chapter16.practice;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ *
+ * Implement a simple LinkedList
+ * You will need to create a LinkedListNode class, which represents each item/node in the linked list
+ * Assume that the elements in the linked list are all of type int
+ * Required functionality...
+ * - head(): get head of list
+ * - tail(): get tail of list
+ * - add(): add to tail of list
+ * - push(): push to head of list
+ * - pop(): remove head of list
+ * - toString(): return a String representation of the list
+ */
+
+public class LinkedList {
+
+    public static void main(String[] args) {
+        // write your code here
+
+    }
+}
+
+class LinkedListNode {}

src/com/codefortomorrow/advanced/chapter16/solutions/LinkedList.java

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+package com.codefortomorrow.advanced.chapter16.solutions;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ *
+ * Implement a simple LinkedList
+ * You will need to create a LinkedListNode class, which represents each item/node in the linked list
+ * Assume that the elements in the linked list are all of type int
+ * Required functionality...
+ * - head(): get head of list
+ * - tail(): get tail of list
+ * - add(): add to tail of list
+ * - push(): push to head of list
+ * - pop(): remove head of list
+ * - toString(): return a String representation of the list
+ */
+
+public class LinkedList {
+
+    private LinkedListNode head;
+
+    /**
+     * default constructor
+     */
+    public LinkedList() {
+        head = null;
+    }
+
+    /**
+     * constructor with first value
+     * @param value  first element in the linked list
+     */
+    public LinkedList(int value) {
+        // create first node
+        head = new LinkedListNode(value, null);
+    }
+
+    /**
+     * get head of Linked List
+     * @return first element of the linked list
+     */
+    public LinkedListNode head() {
+        return this.head;
+    }
+
+    /**
+     * traverse and get tail of linked list
+     * @return last element of the linked list
+     */
+    public LinkedListNode tail() {
+        LinkedListNode current = head;
+        if (current == null) return null;
+
+        while (current.next() != null) {
+            current = current.next();
+        }
+
+        return current;
+    }
+
+    /**
+     * add new element (node) to linked list
+     * @param value  element to add to the end of the linked list
+     */
+    public void add(int value) {
+        LinkedListNode tail = tail();
+        if (tail == null) {
+            head = new LinkedListNode(value, null);
+        } else {
+            tail.setNext(new LinkedListNode(value, null));
+        }
+    }
+
+    /**
+     * push (add element to head of linkedlist)
+     */
+    public void push(int value) {
+        LinkedListNode newHead = new LinkedListNode(value, head);
+        head = newHead;
+    }
+
+    /**
+     * pop (remove and return head of linkedlist)
+     * @return the node that was removed
+     */
+    public LinkedListNode pop() {
+        LinkedListNode popped = head;
+        head = head.next();
+        return popped;
+    }
+
+    /**
+     * Returns a String version of the LinkedList
+     * @return a String version of the LinkedList
+     */
+    @Override
+    public String toString() {
+        String list = "[";
+        LinkedListNode current = head;
+        if (current == null) return null;
+        do {
+            list += Integer.toString(current.value()) + ", ";
+            current = current.next();
+        } while (current != null);
+
+        // Remove trailing comma and space after last list element
+        list = list.substring(0, list.length() - 2);
+        return list + "]";
+    }
+}
+
+class Node {
+
+    private int value;
+
+    /**
+     * Constructs a list node with the given value
+     * @param value  the value stored in this Node
+     */
+    public Node(int value) {
+        this.value = value;
+    }
+
+    /**
+     * Returns the value of this Node
+     * @return the value of this Node
+     */
+    public int value() {
+        return this.value;
+    }
+}
+
+class LinkedListNode extends Node {
+
+    private LinkedListNode next;
+
+    /**
+     * Constructs a LinkedListNode
+     * @param value  the value stored in this node
+     * @param next  the next node
+     */
+    public LinkedListNode(int value, LinkedListNode next) {
+        super(value);
+        this.next = next;
+    }
+
+    /**
+     * Returns the next node
+     * @return the next node
+     */
+    public LinkedListNode next() {
+        return this.next;
+    }
+
+    /**
+     * Sets the next node
+     * @param next  the next node
+     */
+    public void setNext(LinkedListNode next) {
+        this.next = next;
+        return;
+    }
+}

src/com/codefortomorrow/beginner/chapter1/practice/Comments.java

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+package com.codefortomorrow.beginner.chapter1.practice;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ * 
+ * You'll be writing your first ever comment today! 
+ * What we'll go over: 
+ * - single line comments
+ * - multi line comments
+ */
+
+ // a class is an "object" where we will place all our code inside
+ public class Comments {
+     // the main method (below) is the first thing that runs when your program is run
+    public static void main(String[] args) {
+        // this is a single line comment, I can write anything here
+        // single line comments aren't run by Java!
+        // they can be used to annotate your code!
+
+        /**
+         * this is a multi
+         * line
+         * comment
+         * 
+         * It can span across multiple lines!
+         */
+
+        // YOUR ASSIGNMENT: write 1 single-line comment and 1 multi-line comment on the lines below...
+
+
+
+
+
+
+
+    }
+ }

src/com/codefortomorrow/beginner/chapter1/practice/HelloWorld.java

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+package com.codefortomorrow.beginner.chapter1.practice;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ * 
+ * Welcome to Java! 
+ * This may be your first ever java program!
+ * We'll begin your journey with the infamous Hello World program!
+ */
+
+ // a class is an "object" where we will place all our code inside
+ public class HelloWorld {
+    // the main method (below) is the first thing that runs when your program is run
+    public static void main(String[] args) {
+        // write code here (replace the "" with "Hello World!")
+        System.out.println("");
+    }
+ }

src/com/codefortomorrow/beginner/chapter1/solutions/Comments.java

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+package com.codefortomorrow.beginner.chapter1.solutions;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ * 
+ * You'll be writing your first ever comment today! 
+ * What we'll go over: 
+ * - single line comments
+ * - multi line comments
+ */
+
+ // a class is an "object" where we will place all our code inside
+ public class Comments {
+     // the main method (below) is the first thing that runs when your program is run
+    public static void main(String[] args) {
+        // this is a single line comment, I can write anything here
+        // single line comments aren't run by Java!
+        // they can be used to annotate your code!
+
+        /**
+         * this is a multi
+         * line
+         * comment
+         * 
+         * It can span across multiple lines!
+         */
+
+        // YOUR ASSIGNMENT: write 1 single-line comment and 1 multi-line comment on the lines below...
+
+        // Hi my name is Armeet!
+
+        /**
+         * I like teaching Java, and 
+         * good luck on your journey!
+         */
+    }
+ }

src/com/codefortomorrow/beginner/chapter1/solutions/HelloWorld.java

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+package com.codefortomorrow.beginner.chapter1.solutions;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ * 
+ * Welcome to Java! 
+ * This may be your first ever java program!
+ * We'll begin your journey with the infamous Hello World program!
+ */
+
+ // a class is an "object" where we will place all our code inside
+ public class HelloWorld{
+    // the main method (below) is the first thing that runs when your program is run
+    public static void main(String[] args) {
+        // write code here (replace the "" with "Hello World!")
+        System.out.println("Hello World!");
+    }
+ }

src/com/codefortomorrow/beginner/chapter2/practice/ApplesOranges.java

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+package com.codefortomorrow.beginner.chapter2.practice;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ * 
+ * Print out the number of apples and oranges!
+ */
+
+ public class ApplesOranges {
+    public static void main(String[] args) {
+        // write your code here
+
+        // define an integer variable called numOranges with value 10 (line 15)
+
+
+        // define an integer variable called numApples with value 24 (line 18)
+
+
+        // print out number of oranges using variables, output: "I have 10 oranges." (line 21)
+
+
+        // print out number of apples using variables, output: "I have 24 apples." (line 24)
+
+
+    }
+ }
+

src/com/codefortomorrow/beginner/chapter2/practice/VariableTypes.java

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+package com.codefortomorrow.beginner.chapter2.practice;
+
+/**
+ * @author ArmeetJatyani
+ * March 2021
+ * 
+ * Define different types of variables
+ */
+
+ public class VariableTypes {
+    public static void main(String[] args) {
+        // write your code here
+
+        // define an integer variable on line 15
+
+
+        // define a float variable on line 18
+
+
+        // define a double variable on line 21
+
+
+        // define a boolean variable on line 24 (Hint: true/false)
+
+
+        // define a character variable on line 27
+
+
+        // define a string variable on line 30 
+
+
+    }
+ }
+