Noulakaz

The blog of Avinash, Christina, Anya and Kyan Meetoo.

Education

Beware of type erasure in Java

By 13 Comments

This Java program I got from a blog does not compile:

import java.util.*;

class Egg
{
}

class Muffin
{
}

public class Breakfast
{
  private List<Egg> eggs;
  private List<Muffin> muffins;

  public void add(List<Egg> moreEggs) {
    this.eggs.addAll(moreEggs);
  }

  public void add(List<Muffin> moreMuffins) {
    this.muffins.addAll(moreMuffins);
  }
}

The error message is:

name clash: add(java.util.List<Muffin>) and add(java.util.List<Egg>) have the same erasure

I was amazed when I saw that. I finally found an explanation in this forum.

What is happening is that (I quote) “Parameterized types (aka Generics) are only to restrict the use to enter the right object into the collection. All the generic information is erased by the compiler.”

So that why I got a name clash error. Both add(java.util.List<Muffin>) and add(java.util.List<Egg>) are in fact the same method add(java.util.List)!!!

Generics in Java are only used at compile time. They don’t even exist at run time!

PS:

I am a fan of Erasure, the group. Vince Clark was the initiator of Depeche Mode after all…

Declining interest in Computer Science

By 39 Comments

As written here:

An analysis of survey results from the Higher Education Research Institute at the University of California at Los Angeles (HERI/UCLA) indicates that the popularity of computer science (CS) as a major among incoming [first year students] at all undergraduate institutions has dropped significantly in the past four years.

The survey was made in 2005 and the Higher Education Research Institute people only looked at US universities. Nevertheless, I think that this trend is general and is relatively easy to understand.

The first peak, which happened around 1983, was when the microcomputer became pervasive. Suddenly, computers were affordable and many people could finally afford to buy one. This was the era of the Sinclair ZX Spectrum and the Commodore 64. Geeks could finally opt to join a department full of other geeks :-)

The decline from 1986 to 1996 was when people realized that having (or even liking) a computer at home to play games does not make you a Computer Scientist. Being a Computer Scientist implies thinking like a Computer Scientist and not merely liking computers…

The second peak, which happened around 2000, was when Internet came together with its bubble. Lots of youngsters chose CS as they wanted to create the new IBMs and Microsofts. They wanted to emulate Google and Yahoo! and they thought this was easy.

The decline from 2000 onwards was when people found out that emulating Google and Yahoo! was not easy. Sure, they loved to browse the web but they could not build a successful company. And the whole Western economy nearly crashed!

The situation in Mauritius

According to my observations, we had a peak a few years ago when people started talking about the Cyberisland concept. Lots of youngsters chose CS because they dreamed of working in the Cybertower to get a lot of money. This is when lots of centers offering “computer” courses appeared out of nowhere…

Since then, I have notice a decline. Many youngsters have realized that one needs the correct aptitudes to succeed in CS. If someone does not have those aptitudes, then it’s much better for that person to choose something else where he/she has a much higher probability of succeeding. They have also found out that things are not that rosy in the Cybertower…

This is a good thing in my opinion.

Mauritius is a small country with few resources. It’s so much better to let people chose their career based on their aptitudes. Some will become great Computer Scientists. And some will become great singers. That’s how it works everywhere else.

Ask Michael Jackson and Michael Jackson.

Google provides email to UoM students

By 32 Comments

The University of Mauritius is now using Google Apps to provide enhanced services to all 6000 students. They will get:

  • GMail = a web-based mail client with chat facilities with 2Gb of storage,
  • Calendar = with collaborative features i.e. perfect for organizing meetings,
  • Docs = collaborative online word-processor compatible with Word and the OpenDocument Format,
  • Spreadsheet = collaborative online spreadsheet compatible with Excel and the OpenDocument Format.

Let’s hope that the bandwidth the students have at university will be sufficient for them to use these apps!

The students will also have the possibility to read and write emails from their mobile phones using either a customized web interface to Gmail or a nifty Gmail Java application which Google offers for free. (Crap! The application only works with Blackberry devices!)

What is cool is that everything is powered by Linux and Open Source Software.

I am happy :-)