Model a Student

public class Student {
    private String studentId;
    private String name;
    private String email;

    public Student(String studentId, String name, String email) {
        this.studentId = studentId;
        this.name = name;
        this.email = email;
    }

    public String getStudentId() {
        return studentId;
    }

    public String getName() {
        return name;
    }

    public String describe() {
        return name + ' (' + studentId + ')';
    }
}

1. public class Student { — the class.
2. private String studentId; — private — nothing outside Student can silently overwrite this once it's set.
3. private String name; — same protection.
4. private String email; — same protection.
5. (blank line)
6. public Student(String studentId, String name, String email) { — the constructor — the only place these fields are ever set.
7. this.studentId = studentId; — sets the id.
8. this.name = name; — sets the name.
9. this.email = email; — sets the email.
10. } — closes the constructor.
11. (blank line)
12. public String getStudentId() { — a controlled, read-only window onto the id.
13. return studentId; — returns it.
14. } — closes the method.
15. (blank line)
16. public String getName() { — a controlled, read-only window onto the name.
17. return name; — returns it.
18. } — closes the method.
19. (blank line)
20. public String describe() { — a human-readable summary.
21. return name + ' (' + studentId + ')'; — combines both fields into one string.
22. } — closes the method.
23. } — closes the class.

This is exactly the encapsulation pattern from Module 11: private fields, set once through the constructor, exposed through controlled public getter methods.

Student alice = new Student('S001', 'Alice Nkosi', 'alice@example.com');
Student ben = new Student('S002', 'Ben Dlamini', 'ben@example.com');

System.debug(alice.describe()); // "Alice Nkosi (S001)"
System.debug(ben.describe());   // "Ben Dlamini (S002)"

1. Student alice = new Student('S001', 'Alice Nkosi', 'alice@example.com'); — creates the first student, running the constructor.
2. Student ben = new Student('S002', 'Ben Dlamini', 'ben@example.com'); — creates a second, completely independent student.
3. (blank line)
4. System.debug(alice.describe()); — logs "Alice Nkosi (S001)".
5. System.debug(ben.describe()); — logs "Ben Dlamini (S002)" — each object's own data, exactly as the object model from Module 10 predicts.