Classes and encapsulation

public class Course {
    private String title;
    private double price;

    public Course(String title, double price) {
        this.title = title;
        this.price = price;
    }

    public String describe() {
        return title + " -- $" + price;
    }
}

private fields with public methods is the standard Java encapsulation pattern -- callers interact through describe(), never touching title or price directly.