COMP 110-003 Spring 2013
Lab 2
10 Points
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 Eclipse (You
will need to create a new Java Project called lab2 and a new
Java Class called StringFun), and compile and run the program.
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 7 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 7 for a reference. (choose a band
that has more that 5 characters in the name.)
Type casting
is more commonly done between integers and floating-point
numbers. Often when performing arithmetic operations between
the two types.
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 Section 2.2 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 —
refer to Figure 2.5. The lecture notes are not enough. 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 string. Then display the
substring starting at the next index past the first
space)
Part 3
Modular Arithmetic (Solve these problems, Remember you are
calculating the remainder)
Check your answers in a Java program if you are unsure.
Grading
I will check the screen output on your computer during lab time(this one or any one in the future). Each hollow circle bullet in Part 2 is worth 2 points. You are not allowed to cooperate. The exception is that you can discuss the algorithm for the last bullet. There is no specific deadline but start early so that you'll not miss Lab 3's deadline (Lab 3 is based on Lab 2 and you will submit Lab 3 through Sakai.)