Question

Add more methods to SmartPhone.

• hasPhoneNumber: return true if the phone number has been initialized
• getAreaCode: returns the area code of the phone number
• getPrefix: returns the prefix of the phone number
• getLineNumber: returns the line number of the phone number.

Given Files:

public class Phone
{
    protected String name;
    protected long number;

    public Phone() {
        this("None", -1);
    }

    public Phone(String name) {
        this(name, -1);
    }

    public Phone(String name, long number) {
        this.name = name;
        this.number = number;
    }

    public String getName() {
        return name;
    }

    public long getNumber() {
        return number;
    }
}

And:

public class Demo3 {

    public static void test(SmartPhone f)
    {
        System.out.print(f);
        if (f.hasPhoneNumber()) {
            System.out.println("Area code: " + f.getAreaCode());
            System.out.println("Prefix: " + f.getPrefix());
            System.out.println("Line number: " + f.getLineNumber());
        }
        System.out.println();
    }

    public static void main(String[] args) {
        SmartPhone test1 = new SmartPhone("Bret", "1234567890");
        SmartPhone test2 = new SmartPhone("Alice", "8059226966", "[email protected]");
        SmartPhone test3 = new SmartPhone();
        test(test1);
        test(test2);
        test(test3);
    }

}

And:

public class SmartPhone extends Phone
{
    private String email;
    private String phone;
    private String phone2;

    public SmartPhone()
    {
        super("None",-1);
        phone = "Not set";
        email = "None";
        phone2 = "Not set";
    }

    public SmartPhone(String name, String phone)
    {
        super(name, Long.parseLong(phone));
        this.phone = phone;
        this.email = "None";
    }

    public SmartPhone(String name, String phone, String email)
    {
        super(name, Long.parseLong(phone));
        this.email = email;
        this.phone = phone;
    }

    public String toString()
    {
        return "Name: " + name + "\n" +
                "Phone: " + phone + "\n" +
                "Email: " + email + "\n";
    }
}

////////////////////////////////////////// Output //////////////////////////////////////////

Name: Bret\n
Phone: 1234567890\n
Email: None\n
Area code: 123\n
Prefix: 456\n
Line number: 7890\n
\n
Name: Alice\n
Phone: 8059226966\n
Email: [email protected]\n
Area code: 805\n
Prefix: 922\n
Line number: 6966\n
\n
Name: None\n
Phone: Not set\n
Email: None\n
\n

Answer 1

public class SmartPhone extends Phone
{
    private String email;
    private String phone;
    private String phone2;

    public SmartPhone()
    {
        super("None",-1);
        phone = "Not set";
        email = "None";
        phone2 = "Not set";
    }

    public SmartPhone(String name, String phone)
    {
        super(name, Long.parseLong(phone));
        this.phone = phone;
        this.email = "None";
    }

    public SmartPhone(String name, String phone, String email)
    {
        super(name, Long.parseLong(phone));
        this.email = email;
        this.phone = phone;
    }

    public String toString()
    {
        return "Name: " + name + "\n" +
                "Phone: " + phone + "\n" +
                "Email: " + email + "\n";
    }

    public boolean hasPhoneNumber() {
        return !phone.equals("Not set");
    }

    public String getAreaCode() {
        return phone.substring(0, 3);
    }

    public String getPrefix() {
        return phone.substring(3, 6);
    }

    public String getLineNumber() {
        return phone.substring(6);
    }
}