Machine Problem 1

Background

Start with the classic Java "Hello World" program:

// HelloWorld.java
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World.");
    }
}

java HelloWorld this and that

Then

• args.length will be 3,
• args[0] will be this,
• args[1] will be and,
• args[2] will be that, and
• and trying to use args[3] will throw an exception.

The Assignment

Make a Java program that:

• Is in a single file called Args.java, with the class holding the main method named as Java requires.
• The shell command javac Args.java compiles your program.
• The shell command java Args runs your program.
• If run with no additional command line arguments, it outputs the message No arguments.
• If run with arguments, it prints them out, one per line. For example, given the command java Args this and that the output should be:

  args[0] = this
  args[1] = and
  args[2] = that
  

• Your code should be written largely in conformance with the Java Code Conventions originally published by Sun and now on Oracle's web site.
• Your program must include an author attribution in the Javadoc style illustrated in the course notes. (This style is a newer development than the comment style suggested in section 3.1.1 of the Code Conventions.) Give the date on which you completed the assignment as the version number.

Submission

On or before the end of Monday, Feb. 8, you must submit your program using the following shell command on the fastx machine:

~dwjones/submit xxxx Args.java

Substitute your section number for xxxx above, but do not alter the text dwjones.

The program will confirm that you successfully submitted your solution with the message "submiter: succesfull submission of xxxx/HawkID" with xxxx replaced with your section number and HawkID replaced with your HawkID.

You may submit as many times as you want. The last successful submission is the one that will count. As such, it is a good idea to submit as soon as you have code that sort-of works, submit again when you have code that works the way you like, and perhaps submit again when you bring your code up to the highest standard of readability.

Grading

Code that executes correctly is worth half credit (2.0 out of 5 points). The remaining credit is all for readability. Expect demerits for:

• Overlength lines
• Sloppy indenting
• Excessive whitespace
• Insufficient whitespace
• Excessive comments
• Insufficient comments

Student Questions

A student asked: Do we have to include our name in the file even if we are the only author?

A student asked: for the section we type in for submitting, is that the class section (0AAA) or the discussion section (0A01)?

A student asked: I get this message "Error: Could not find or load main class Args.java"

A student asked: When I try to write in-line comments on my for loop, it gets too long. What's the best way to deal with this?

// for all items in the whazzit ...
for (long initialization; long termination rule; long increment code) {
    loop body;
}

for (long initialization; long termination rule; long increment code) {
    // item.thisone is one item in the whazzit ...
    loop body;
}

A student asked: You said "the Javadoc style illustrated in the course notes." Where is that?

A student asked: You mentioned a format program we could run on our code.

~dwjones/format *.java