Trick Question

Today at school we went over the answers of the test we took last time. There was one questions I got totally wrong. A couple people including myself grumbled that it was a trick question. The instructor said it came straight out of the book.

Here is the question: What does the following code snippet output:

int n=0;
for (n=4; n > 0; n--);
{
System.out.println(n);
}

Here is a hint. There is only one line in the output. At first I protested. Surely this code should have 4 lines of output. The loop iterates through four times after all.

The trick was that there was a semicolon directly after the for loop. Therefore the loop has a body which was empty. After the loop finished, n equals 0. Then the program executes one println statement. Yeah. That's an evil question. Now I know better. Watch out for the tricks.

Libjcsi to the Rescue

I have previously written about my recent exploits in the game development field. To make sure I gain Java programming skills during this exercise, I am writing the whole game in Java. So far I tried rolling my own graphics drawing code. That turned out to be difficult. Some output looked ok. Other graphics were slightly off. This was painful.

Another developer recommended that I use their graphics package libjcsi. This package covers simplifies console output for you. I tried compiling their sample program. In 10 minutes I had a graphical user interface up and running. In an hour I had a bare bones screen of my game going. I was pleasantly surprised that this package also handled keyboard input. So I quickly coded up user input to control the direction of the main character. I now got a guy running around my simple screen. Life is good.

Next I think I will try to place objects on the screen that represent gold. Then if the user walks over top the gold, I want to register that the user picked the gold up. These all seem like baby steps. But once I get the basics down, I can rocket into more complex ideas I have about my game. I will say that I still do not have the hang of Java packages. Perhaps by the time I complete my game, I will have them nailed down.