Programming Assignment Checklist: Hello World

Questionnaire

Did you remember to fill out the brief questionnaire?

Goals

Regardless of the operating system that you choose, the goal of Assignment 0 is to make sure that you can:

• Find relevant material from the course web page and booksite.

• Edit, compile, and execute a Java program.

• Submit your assignment electronically via Dropbox.
  Note: you won't be able to submit an assignment until you are registered in SCORE for a precept.

Frequently Asked Questions

What's a checklist? The programming assignment specifies the general programming assignment. The checklist contains supplemental information, and you are expected to read it prior to submitting your work. Some examples include: links to any preliminary code, a readme.txt template, hints, and frequently asked questions.

What preparation do I need to complete this assignment? Read Section 1.1 and 1.2 of the textbook. If you don't understand something, email or visit your preceptor for assistance. Don't be bashful about asking for help.

Can I use the booksite instead of the textbook? No, the booksite is a super-condensed version of the textbook; it is suitable for reference while online (for example, while programming). The textbook is intended for use when initially learning new material and when reinforcing your understanding of that material (for example, when reviewing for an exam).

How can I download a program from the textbook? The corresponding section in the booksite contains links to all of the Java programs in the textbook. The link goes to a .java.html file (such as UseArgument.java.html) that is suitable for display in a browser. You can cut-and-paste the code into DrJava as needed. The .java.html file also contains a link to the .java file (such as UseArgument.java); you can right click this link and save the file to your computer.

I don't understand all of the jargon in HelloWorld.java. Should I drop the course? Don't worry—we'll explain this in the first or second precept. Do the readings and bring any lingering questions to precept.

Do I have to use DrJava? No, feel free to use any development environment you like.

How do I open the plain text file, readme.txt? What program should I use to edit the readme.txt file? It is an amazing fact that .txt files are not consistently formatted in modern systems. If you want to be sure that we can read your .txt files (and we think that you do!) please use DrJava, as follows:

• In DrJava, select File -> Open; select the desired directory; choose All Files under File Format.
• Be careful to save the file as readme.txt and not as a .java file.

The readme.txt file must be a plain text file—Microsoft Word .doc or .docx formats and Mac TextEdit .rtf formats are unacceptable.

How should I read in user input? Use command-line arguments as specified in the assignment and described in Section 1.2 of the textbook. You will receive a significant deduction for not following directions. We will learn about more general ways to handle user input in Section 1.5.

What's Dropbox? Dropbox is a system that we developed for submitting assignments here in the CS department at Princeton. We do not use Blackboard for this purpose in this course. Our Dropbox is not be be mistaken for the cloud file-sharing system that has become prominent on the web in recent years.

Every assignment has a link to its own dropbox. Look on the Assignments page, in the submit column. You can also go to the general dropbox page via https://dropbox.cs.princeton.edu. Either way, you will need to login.

When I login to Dropbox, my browser asks me whether I should accept a "security certificate." How should I proceed? Accept it permanently. We need to establish a secure connection so that you can submit assignments with reasonable privacy.

When I submit HelloWorld.java, Dropbox does not seem to accept it. Why not? Be sure the file is named HelloWorld.java. The capitalization and .java extension are important. Also, be aware that DrJava creates backup files with a .java~ extension, so be sure that you don't submit these. If you use Windows, we recommend configuring your system to unhide the filetype extensions.

Submission

Submission. All assignments submissions are electronic, using Dropbox. We do not accept email or hardcopy submissions. Here are some guidelines.

• The assignment (and Dropbox submission form) specifies exactly which filenames to use. These names are case-sensitive (even if your operating system is not case-sensitive). We begin grading your submissions by running an automated script. You will lose a substantial number of points if you don't follow these instructions.

• Do not submit .class files. Our grading script automatically compiles your .java files.

• When you submit, be sure to hit the Check All Submitted Files button. Make sure that you submitted the right files and that they compile cleanly. You risk losing a substantial number of points if you submit a file that does not compile correctly.

• You may resubmit a file after making corrections by uploading the file again.

• Be sure that every file you submit includes your name, login, and precept number.

• The readme.txt file is a narrative description of the work you did on your program. This is the first thing the grader will read. Each week, we'll provide a template readme.txt file. Be sure to answer any questions that it contains.

Formatting.

• Format your code consistently. Use 4 spaces for each indentation level. (If you followed our instructions, DrJava will already be configured to do this.) DrJava can automatically re-indent your code: highlight a block of code and hit the Tab key.

• Do not use hard tabs. (If you are using DrJava, you are all set.) Different systems and tools display and print hard tabs differently. Hard tabs are obsolete: in ancient times, they were used for data compression. Modern text editors support soft tabs, which automatically substitute spaces for tabs.

• Do not exceed 80 characters per line. Long lines are hard to read and will annoy your grader (who may deduct style points). Use line breaks as needed. This rule also applies to the readme.txt file.

Enrichment

Here is Hello World in over 200 different programming languages.