COMP 110 Spring 2008

Description

Lab 2 will introduce you to Java applets, string manipulation, and type casting. You have been given a skeleton program StringFun.java that can be found on the course webpage. Copy the program into jGrasp, and compile and run the program. (Don't forget to change the header!)

Part 1

Characters are stored as numbers in a computer. This java applet converts the input integer to the unique Unicode character stored as that number. Appendix 3 has a subset of the Unicode character set. Note: the input integer was type cast as a character.
(char)inputInt

• Comment out the first JOption line and uncomment the second JOption line. Recompile and run the program.
• The second display box should now say Rocks!
• Add your favorite band's name to the dialog box by type casting Unicode characters. Start the name of your band after the "". Use Appendix 3 for a reference. (choose a band that has more that 5 characters in the name.)

Part 2

For this part of the lab you will modify the code StringFun.java to prompt the user for a string (of characters) and output information about the string as well as manipulate the input string. You will be referencing pages 80-82 of your textbook.

• Declare a variable of Type String to be your input string with identifier inputString.
• Prompt the user to input a string.
  inputString = JOptionPane.showInputDialog("Please Enter a string:");
  This line of code will prompt the user and store the input string in inputString
• Manipulate the string stored in inputString - reference pages 80-82. For each step, print out a new dialog box using
  JOptionPane.showMessageDialog(null, your output goes here);
• Output the length of inputString
• Convert inputString to all uppercase letters
• Print out the characters at positions 0 and 5 (assume the user input a string with more than 6 characters)
• Display the substring starting at position 0 and ending at position 5
• Display the inputString without the first word. (Hint: find the index of the first space in the sting. Then display the substring starting at the next index past the first space)

Additional Questions

• What was the most helpful part of this lab? least helpful?
• Has any part of lecture been confusing that you would like covered again? What?
• Modular Arithmetic (Solve these problems, Remember you are calculating the remainder)
  • 21 % 5
  • 47 % 12
  • 72 % 60

Grading

• 5 points Part 1
• 15 point Part 2
• 3 points Declaring variables and display prompt
• 12 points String Manipulation
• 3 points Additional Questions
• 2 points Handing in the assignment correctly on the first try

How to hand in the assignment

• A file named yourlastname_lab2.txt, where yourlastname is your last name, that provides answers to the Additional Questions. Make sure the file has the appropriate header.
• A file named yourlastname_lab2.jar, where yourlastname is your last name. The .jar file should include only StringFun.java. Your java files should have the appropriate header. Follow these instruction to create yourlastname_lab2.jar.
• Attach yourlastname_lab2.txt and yourlastname_lab2.jar to an email with subject COMP110 Lab 2 yourlastname to tpeck@cs.unc.edu by 3:00 Friday February 1.
• If you do not follow these instructions you will not get credit for the lab. Please let me know if you are having any problems with the assignment submission process.