Conformed to Java conventions and updated all directories of Chapter 6.

src/main/java/chapter06/bmi/Bmi.java

@@ -1,65 +1,75 @@
-package chapter06.bmi;// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+package chapter06.bmi;
+
 import java.awt.*;
 import java.awt.event.*;
 import javax.swing.*;
 import java.text.DecimalFormat;
 
-public class Bmi extends JFrame
-  implements ActionListener
-{
-  JTextField inputLbs, inputInches, displayBmi;
+/**
+ * A {@link JFrame} window that calculates BMI from pounds and inches.
+ */
+public class Bmi extends JFrame implements ActionListener {
+    private JTextField massInputField;
+    private JTextField heightInputField;
+    private JTextField bmiDisplayField;
 
-  public Bmi()
-  {
-    super("BMI Calculator");
-    JLabel labelLbs = new JLabel("Weight (lbs):", SwingConstants.RIGHT);
-    inputLbs = new JTextField(5);
-    JLabel labelInches = new JLabel("Height (inches):", SwingConstants.RIGHT);
-    inputInches = new JTextField(5);
-    JLabel labelBmi = new JLabel("BMI = ", SwingConstants.RIGHT);
-    displayBmi = new JTextField(5);
-    displayBmi.setEditable(false);
-    JButton go = new JButton("Compute");
-    go.addActionListener(this);
+    public Bmi() {
+        super("BMI Calculator");
+        JLabel labelLbs = new JLabel("Weight (lbs.):", SwingConstants.RIGHT);
+        massInputField = new JTextField(5);
+        JLabel labelInches = new JLabel("Height (in.):", SwingConstants.RIGHT);
+        heightInputField = new JTextField(5);
+        JLabel labelBmi = new JLabel("BMI = ", SwingConstants.RIGHT);
+        bmiDisplayField = new JTextField(5);
+        bmiDisplayField.setEditable(false);
+        JButton go = new JButton("Compute");
+        go.addActionListener(this);
 
-    Container c = getContentPane();
-    c.setBackground(Color.white);
-    JPanel p = new JPanel();
-    p.setLayout(new GridLayout(3, 2, 5, 5));
-    p.add(labelLbs);
-    p.add(inputLbs);
-    p.add(labelInches);
-    p.add(inputInches);
-    p.add(labelBmi);
-    p.add(displayBmi);
-    c.add(p, BorderLayout.CENTER);
-    c.add(go, BorderLayout.SOUTH);
-  }
+        Container c = getContentPane();
+        c.setBackground(Color.white);
+        JPanel panel = new JPanel();
+        panel.setLayout(new GridLayout(3, 2, 5, 5));
+        panel.add(labelLbs);
+        panel.add(massInputField);
+        panel.add(labelInches);
+        panel.add(heightInputField);
+        panel.add(labelBmi);
+        panel.add(bmiDisplayField);
+        c.add(panel, BorderLayout.CENTER);
+        c.add(go, BorderLayout.SOUTH);
+    }
 
-  public void actionPerformed(ActionEvent e)
-  {
-    int lbs = Integer.parseInt(inputLbs.getText());
-    int inches = Integer.parseInt(inputInches.getText());
-    double bmi = calculateBmi(lbs, inches);
-    DecimalFormat df = new DecimalFormat("00.0");
-    displayBmi.setText(df.format(bmi));
-  }
+    /**
+     * Called when the "Compute" button is clicked.
+     * @throws NumberFormatException when non-integers are entered into the height and mass input fields. Input
+     * verification should be used to mitigate this.
+     */
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        int pounds = Integer.parseInt(massInputField.getText());
+        int inches = Integer.parseInt(heightInputField.getText());
+        double bmi = calculateBmi(pounds, inches);
+        DecimalFormat df = new DecimalFormat("00.0");
+        bmiDisplayField.setText(df.format(bmi));
+    }
 
-  // Returns BMI equal to weight in kilograms divided
-  // over squared height in meters.
-  private double calculateBmi(int lbs, int inches)
-  {
-	  double kg, meters;
-	  kg = lbs * 0.454;
-	  meters = inches * 0.0254;
-	  return kg/(meters * meters);
-  }
+    /**
+     * Calculates body mass index.
+     * @param pounds mass in pounds.
+     * @param inches height in inches.
+     * @return BMI in kilograms per square meter.
+     */
+    private double calculateBmi(int pounds, int inches) {
+        double kilograms = pounds * 0.454;
+        double meters = inches * 0.0254;
+        return kilograms / Math.pow(meters, 2);
+    }
 
-  public static void main(String[] args)
-  {
-    Bmi w = new Bmi();
-    w.setBounds(300, 300, 300, 160);
-    w.setDefaultCloseOperation(EXIT_ON_CLOSE);
-    w.setVisible(true);
-  }
+    public static void main(String[] args) {
+        Bmi w = new Bmi();
+        w.setBounds(300, 300, 300, 160);
+        w.setDefaultCloseOperation(EXIT_ON_CLOSE);
+        w.setVisible(true);
+    }
 }

src/main/java/chapter06/dogyears/DogYearsConverter.java

@@ -0,0 +1,30 @@
+// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+package chapter06.dogyears;
+
+import java.lang.Math;
+
+/**
+ * A class that provides a method to convert dog years to human years.
+ */
+public class DogYearsConverter {
+    private static final double DOG_TO_HUMAN_YEAR_RATE = 5.3333333333;
+
+    /**
+     * Converts the given age in dog years to the equivalent age in human years.
+     * @param dogYears an age in dog years.
+     * @return the age in human years. If zero or a negative integer was passed, this returns zero.
+     */
+    public static int convertToHumanAge(int dogYears) {
+        double dogAge = 0;
+
+        if (dogYears > 0) {
+            dogAge += 13;
+            dogAge += DOG_TO_HUMAN_YEAR_RATE * (dogYears - 1);
+        }
+        return (int) Math.round(dogAge);
+    }
+
+    public static void main(String[] args) {
+        System.out.println("The dog's age is: " + convertToHumanAge(3));
+    }
+}

src/main/java/chapter06/piechart/Poll.java

@@ -1,28 +1,28 @@
-package chapter06.piechart;// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+package chapter06.piechart;
+
 import java.awt.*;
 import javax.swing.*;
 
-public class Poll extends JFrame
-{
-  public Poll()
-  {
-	
-    super("Vote for Tami, Brian, or Liz");
+/**
+ * A {@link JFrame} window that
+ */
+public class Poll extends JFrame {
+    public Poll() {
+        super("Vote for Tami, Brian, or Liz");
 
-    Container c = getContentPane();
-    c.setBackground(Color.WHITE);
-    PollDisplayPanel chart = new PollDisplayPanel("Tami", "Brian", "Liz");
-    PollControlPanel controls = new PollControlPanel(chart);
-    c.add(chart, BorderLayout.CENTER);
-    c.add(controls, BorderLayout.SOUTH);
-  }
+        Container c = getContentPane();
+        c.setBackground(Color.WHITE);
+        PollDisplayPanel chart = new PollDisplayPanel("Tami", "Brian", "Liz");
+        PollControlPanel controls = new PollControlPanel(chart);
+        c.add(chart, BorderLayout.CENTER);
+        c.add(controls, BorderLayout.SOUTH);
+    }
 
-  public static void main(String[] args)
-  {
-
-      Poll w = new Poll();
-      w.setBounds(300, 300, 400, 400);
-      w.setDefaultCloseOperation(EXIT_ON_CLOSE);
-      w.setVisible(true);
-  }
+    public static void main(String[] args) {
+        Poll w = new Poll();
+        w.setBounds(300, 300, 400, 400);
+        w.setDefaultCloseOperation(EXIT_ON_CLOSE);
+        w.setVisible(true);
+    }
 }

src/main/java/chapter06/piechart/PollControlPanel.java

@@ -1,56 +1,52 @@
-package chapter06.piechart;// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+// Code written as part of the Java-Methods-Program-AP-Comp-A-2021-2022 repository on GitHub.
+package chapter06.piechart;
 
-/*
- * Implements the control panel for the chapter06.piechart.Poll program
- */
 import java.awt.*;
 import java.awt.event.*;
 import javax.swing.*;
 
-public class PollControlPanel extends JPanel
-                          implements ActionListener
-{
-  private JButton button1, button2, button3;
-  private PollDisplayPanel chartPanel;
-
-  public PollControlPanel(PollDisplayPanel chart)
-  {
-    chartPanel = chart;
-
-    button1 = new JButton("Tami");
-    button1.setPreferredSize(new Dimension(80, 30));
-    button1.setToolTipText("Vote for Tami");
-    button1.addActionListener(this);
-
-    button2 = new JButton("Brian");
-    button2.setPreferredSize(new Dimension(80, 30));
-    button2.setToolTipText("Vote for Brian");
-    button2.addActionListener(this);
-
-    button3 = new JButton("Liz");
-    button3.setPreferredSize(new Dimension(80, 30));
-    button3.setToolTipText("Vote for Liz");
-    button3.addActionListener(this);
-
-    add(button1);
-    add(button2);
-    add(button3);
-  }
-
-  /**
-   *  Processes button events
-   */
-  public void actionPerformed(ActionEvent e)
-  {
-    JButton button = (JButton)e.getSource();
-
-    if (button == button1)
-      chartPanel.vote1();
-    else if (button == button2)
-      chartPanel.vote2();
-    else if (button == button3)
-      chartPanel.vote3();
-    chartPanel.repaint();
-  }
-
+/**
+ * Implements the control panel for the {@link chapter06.piechart.Poll} program.
+ */
+public class PollControlPanel extends JPanel implements ActionListener {
+    private JButton button1;
+    private JButton button2;
+    private JButton button3;
+    private PollDisplayPanel chartPanel;
+
+    public PollControlPanel(PollDisplayPanel chart) {
+        chartPanel = chart;
+
+        button1 = new JButton("Tami");
+        button1.setPreferredSize(new Dimension(80, 30));
+        button1.setToolTipText("Vote for Tami");
+        button1.addActionListener(this);
+
+        button2 = new JButton("Brian");
+        button2.setPreferredSize(new Dimension(80, 30));
+        button2.setToolTipText("Vote for Brian");
+        button2.addActionListener(this);
+
+        button3 = new JButton("Liz");
+        button3.setPreferredSize(new Dimension(80, 30));
+        button3.setToolTipText("Vote for Liz");
+        button3.addActionListener(this);
+
+        add(button1);
+        add(button2);
+        add(button3);
+    }
+
+    public void actionPerformed(ActionEvent e) {
+        JButton button = (JButton) e.getSource();
+
+        if (button == button1) {
+            chartPanel.vote1();
+        } else if (button == button2) {
+            chartPanel.vote2();
+        } else if (button == button3) {
+            chartPanel.vote3();
+        }
+        chartPanel.repaint();
+    }
 }