Code is STUFF

In English we distinguish between count nouns and non-count or mass nouns. Consider what feels wrong about these sentences:

  • My glass is full of waters.
  • I’ve got sands in my shoes.
  • Could I borrow a money?
  • I want to buy a furniture.

The reason these are wrong is that water, sand, money and furniture are examples of mass nouns. They are STUFF. You cannot pluralize stuff and you cannot refer to “a stuff”.

Why am I telling you this? Because “code”, as in lines of computer code, is also a mass noun. Code is STUFF. You cannot refer to “codes” and you cannot write “a code”.

Please try to remember this!

Java Serialization Example

Java provides a method of saving objects to file, called Serialization. In order for an object to be serializable it must implement the java.io.Serializable interface and you should set a version ID as well as shown below.

class Student implements java.io.Serializable {

   String name = "";
   Integer age = 0;
   Double gpa = 0.0;

   private static final long serialVersionUID = 1L;
}

You can save the object to file like this:

        try {
            FileOutputStream fileOut = new FileOutputStream(path);
            ObjectOutputStream out = new ObjectOutputStream(fileOut);
            out.writeObject(obj);
        } catch (IOException i) {
            i.printStackTrace();
        }

And you can load it like this:

        try {
            FileInputStream fileIn = new FileInputStream(path);
            ObjectInputStream in = new ObjectInputStream(fileIn);
            obj = (Student)in.readObject();
        } catch (FileNotFoundException fnf) {
            System.out.println("No serialized file found at " + path + ". Creating new blank object.");
            obj = new Student();
        }
         catch (Exception e) {
            e.printStackTrace();
        }

Is IB Computer Science for me?

Key things to remember:

About 50% of the course is programming, so you will need to enjoy programming. I have given you a short diagnostic challenge below. If you enjoy trying to solve it, then you should do IB Computer Science.

High school computer science is generally NOT a pre-requisite to study computer science at university, so you can do computer science later, even if you don’t do it now. This is not true of other subjects like chemistry and physics.

I don’t set homework outside of reviewing what we’ve done in class and revision for summative assessments. All summative assessments take the form of written tests in the style of the IB Computer Science exam. There are three per semester, including end-of-year and mock examinations. That’s not a lot of tests, but I will expect you to have prepared well.

As with all IB subjects you will have a substantial internally assessed project. In IB Computer Science this takes the form of a software development project in which you must plan, design, code and implement a computer program for a real client.

Do you like programming?

This algorithm prints every item in a list of 100 things.

i = 0
while i < 100:
  print list[i]
  i = i + 1

This algorithm prints every item in the list from back to front.

i = 100
while i > 0:
  print list[i-1]
  i = i - 1

This algorithm prints “Hooray” if it finds the number 7 in the list:

i = 0
while i < 100:
  if list[i] == 7 then:
    output "Hooray"
    break
  i = i + 1

Can you write an algorithm to determine if the list is a palindrome?
(ie it is the same forwards as backwards).