Notes

  • Why Java?

    • More flexible OOP
    • Run an any platform
    • Garbage collection --> memory management, when a variable is no longer used it's
    • Multi-threading: able to acces different

  • Primitives

    • Predefined
    • lovercase
    • ex: boolean, int, double, char, long, short
  • Non-Primitives
    • Strings
    • capital
  • How to name
    • letters, numbers, or underscores
    • final makes variable constant
    • Casting --> changing data types
      • int to a double
      • Narrowing is going from bigger data to smaller
  • Operators
    • +, -, , /, %, ++, --, +=, -=, =, /=, %=
    • Mod returns the remainder
    • overflow errors --> left to right (PEMDAS)
    • Incremet and decrement operators --> adds 1 and subract 1
  • Coding Challenge
  • Scanner
    • import Scanner class

Homework

2006 FRQ

Link to questions

1)
a.

public class Appointment
{
    public boolean conflictsWith (int appointmentTimeInterval, int timeInterval)
    {
        if(appointmentTimeInterval < timeInterval)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
}

Appointment appointment = new Appointment();

boolean conflict = appointment.conflictsWith(10, 2);

System.out.printf("Appointment is at 10\nTime interval is 2\n");
System.out.printf("Is there a conflict with appointment?: %b\n", conflict);

Appointment is at 10
Time interval is 2
Is there a conflict with appointment?: false

java.io.PrintStream@725e0cfd

1)
b.

public class Appointment
{
    public void clearConflicts(Appointment appointment)
  {
    int loop = 0;

    while (loop < appointmentList.size())
    if (((Appointment)appointmentList.get(loop)).conflictsWith(appointment))
    {
        appointmentList.remove(loop);
    }
    else
    {
        loop++;
    }
  }
}

1)
c.

public class Appointment
{
    public boolean addAppointment(Appointment appointment, boolean emergency)
  {
    if (emergency)
    {
      clearConflicts(appointment);
      appointmentList.add(appointment);

      return true;
    }

    for (int loop = 0; loop < appointmentList.size(); loop++)
      if (((Appointment)appointmentList.get(i)).conflictsWith(appointment))
      {
        return false;
      }

    appointmentList.add(appointment);
    return true;
  }
}

2)
a.

double initialPrice = 6.50;

public static double purchasePrice (double tax)
{
    tax *= 1.1;
    return tax;
}

System.out.printf("Before tax: $%.2f\n", initialPrice);
double finalPrice = purchasePrice(initialPrice);

System.out.printf("After tax: $%.2f\n", finalPrice);

Before tax: $6.50
After tax: $7.15

java.io.PrintStream@725e0cfd

3)
a.

public class Customer
{
    private String _name;
    private int _ID;

    public Customer(String name, int IDNum)
    {
        _name = name;
        _ID = IDNum;
    }

    public String getName()
    {
        return _name;
    }

    public int getID()
    {
        return _ID;
    }

    public int compareCustomer (Customer compare)
    {
        int compareIDs = _ID - compare._ID;
        return compareIDs;
    }    
}

// main method
Customer customer1 = new Customer("Smith", 1001);
Customer customer2 = new Customer("Anderson", 1002);
Customer customer3 = new Customer("Smith", 1003);

int compareCustomer1 = customer1.compareCustomer(customer1);
int compareCustomer2 = customer1.compareCustomer(customer2);
int compareCustomer3 = customer1.compareCustomer(customer3);

System.out.printf("Customer 1 compared to Customer 1: %d\n", compareCustomer1);
System.out.printf("Customer 1 compared to Customer 2: %d\n", compareCustomer2);
System.out.printf("Customer 1 compared to Customer 3: %d\n", compareCustomer3);

Customer 1 compared to Customer 1: 0
Customer 1 compared to Customer 2: -1
Customer 1 compared to Customer 3: -2

java.io.PrintStream@725e0cfd