Added starter code for the lesson 4 exercises.

src/org/launchcode/java/demos/lsn4school/Course.java

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+package org.launchcode.java.demos.lsn4school;
+
+import java.util.ArrayList;
+
+public class Course {
+    private String topic;
+    private Teacher instructor;
+    private ArrayList<Student> enrolledStudents;
+
+    // TODO: Add your custom 'toString' method here. Make sure it returns a well-formatted String rather than
+    //  just the class fields.
+
+
+    // TODO: Add your custom 'equals' method here. Consider which fields should match in order to call two
+    //  Course objects equal.
+
+}

src/org/launchcode/java/demos/lsn4school/Student.java

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+package org.launchcode.java.demos.lsn4school;
+
+public class Student {
+
+    private static int nextStudentId = 1;
+    private String name;
+    private int studentId;
+    private int numberOfCredits = 0;
+    private double gpa = 0.0;
+
+    public Student (String name, int studentId, int numberOfCredits, double gpa) {
+        this.name = name;
+        this.studentId = studentId;
+        this.numberOfCredits = numberOfCredits;
+        this.gpa = gpa;
+    }
+
+    public Student(String name, int studentId) {
+        this(name, studentId, 0, 0);
+    }
+
+    public Student(String name) {
+        this(name, nextStudentId);
+        nextStudentId++;
+    }
+
+    public String studentInfo() {
+        return (this.name + " has a GPA of: " + this.gpa);
+    }
+
+    // TODO: Complete the getGradeLevel method here:
+    public String getGradeLevel() {
+        // Determine the grade level of the student based on numberOfCredits
+    }
+
+    // TODO: Complete the addGrade method.
+    public void addGrade(int courseCredits, double grade) {
+        // Update the appropriate fields: numberOfCredits, gpa
+    }
+
+    // TODO: Add your custom 'toString' method here. Make sure it returns a well-formatted String rather
+    //  than just the class fields.
+
+    // TODO: Add your custom 'equals' method here. Consider which fields should match in order to call two
+    //  Student objects equal.
+
+    public String getName() {
+        return name;
+    }
+
+    public int getStudentId() {
+        return studentId;
+    }
+
+    public int getNumberOfCredits() {
+        return numberOfCredits;
+    }
+
+    public double getGpa() {
+        return gpa;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public void setStudentId(int studentId) {
+        this.studentId = studentId;
+    }
+
+    public void setGpa(double gpa) {
+        this.gpa = gpa;
+    }
+
+    private void setNumberOfCredits(int numberOfCredits) {
+        this.numberOfCredits = numberOfCredits;
+    }
+
+    public static void main(String[] args) {
+        Student sally = new Student("Sally",1,1,4.0);
+        System.out.println("The Student class works! " + sally.getName() + " is a student!");
+        System.out.println(sally);
+        sally.addGrade(12, 3.5);
+        System.out.println(sally);
+        sally.addGrade(25, 3.8);
+        System.out.println(sally);
+    }
+}

src/org/launchcode/java/demos/lsn4school/Teacher.java

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+package org.launchcode.java.demos.lsn4school;
+
+public class Teacher {
+    private String firstName;
+    private String lastName;
+    private String subject;
+    private int yearsTeaching;
+
+    public Teacher(String firstName, String lastName, String subject, int yearsTeaching) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.subject = subject;
+        this.yearsTeaching = yearsTeaching;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public void setSubject(String subject) {
+        this.subject = subject;
+    }
+
+    public void setYearsTeaching(int yearsTeaching) {
+        this.yearsTeaching = yearsTeaching;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public String getSubject() {
+        return subject;
+    }
+
+    public int getYearsTeaching() {
+        return yearsTeaching;
+    }
+}