CLASS
NOTES
These are my personal class notes for Java Programming CIS 219
with professor James Habermas at G.C.C. These are MY notes and
NOT a tutorial..Anyone who wishes to use them is welcome. I will try to
keep the information as correct as possible.
Homework assignment 01-21-03
1. Set up J2sdk and TextPad
2. Read appendix A
3. Read chapter 1 1-10 and be able to explain the difference
between an interpreter and a compilerImportant web addresses
SyllabusClass discussion
1. Encapsulate- To enclose in or as if in a capsule. In Java Programming
the main can't touch a private class because it is encapsulated.
2. It is very important to remember Java is CaSe SeNsiTive.
3. public static void is part of all programs
4. ALWAYS name your java file whatever you call your class
i.e.public class addit then you must save the file as addit.java
5. Be sure to line up all curly Qs ( {} )
6. Complete statements end with a statement terminator ; (semi-colon)
7. Literal strings are always in double quotes "
Strings are also known as arguments
8. Java is a WORA programming language
Write
Once
Run
Anywhere
9.Writing comments in Java
// single line comment
/*
*/ block commentingHomework assignment 01-23-03
1. Work on writing small programs (4 to 6 programs over the weekend).
2. Get used to using the information posted above and be able to write
a small program without looking at another one.Class discussion
1. The source code is the program the auther creates in a high level
language such as Java and has a .java extension.
2. When compiling a source code NO NEWS IS GOOD NEWS
When compiling in Dos or on a Linux box you should end up at
the same prompt you start the complie at. i.e. C:\>
3. Compiling in Dos or Linux you must have the .java extension
i.e.javac your_program_name.java
4. javac compiles into byte code.
5. Byte code is a WORA code
6. To RUN the program after it is compiled you type:
java your_program_name without an extension.
7. the symbol .* (wild card) typed after a file name in Dos or Linux will return
all files with that name i.e. dir day01.* will return day01.java, day01.class
if you have compiled the .java file
8. Java is platform independant which means it will run on any machine that
has the JVM (Java Virtual Machine) installed.
9. Syntax are the rules of a high-level programming language.
10. Writing a class gives you the ability to create your own data types.
11.There are 8 primitive data types associated with Java.They are;
INTEGER VARIABLES
byte (8 bit) Stores an integer in the range -128 to +127
short (16 bit) Stores an integer...
int (32 bit) Stores an integer...
long (64 bit) Stores an integer...
REAL NUMBERS
float (32 bit) Single-precision floating point
double (64 bit) Double-precision floating point
OTHER TYPES
boolean Stores True or false value
char (16 bit) Stores a single character
These primitive types can be used by themselves or
to create complex data types called reference types.Homework assignment 01-28-03
1. Read chapter 2 Java Programming second edition
Joyce FarrellClass discussion
1.Two types of Java Programs
a. Applications are stand alone programs that run in a Dos window or on a
Linux box.
b. Applets run on the web in a web browser such as Internet Explorer or
Netscape Navigator.
2. Your browser must be configured to run Java applets on the web. To do
this you must open a browser window go to Tools \ internet options \ advanced
and scroll down to Java (Sun) and make sure the box is checked to run applets
using Java(Sun) instead of Microsoft VM.
Then YOU MUST RESTART YOUR COMPUTER for the changes to take effect.
3. Syntax errors are usually spelling errors.
4. Logic errors are usually math errors
5. An integer (int), which is a primitive data type, reserves four (4) bytes of ram for storage. Each byte has eight (8) bits of information.
6. Avoid using reserved words (pg 9) for naming classes or variables.
7. When writing classes your variable must be defined and the data type
you choose should be capitalized. For instance, if you needed a variable
for a timer you might use clockTimer for the variable and the and the data type
might me Timer You would write it like this: Timer clockTimer;
8. Classes are reusable and must me stored in your classes folder in
j2sdk1.4.0 \ classes so they are recognized by the javac.exe when
you reuse them.Class discussion
1.Review from Tuesday class discussion.
2. Primitive data types actually store the information in RAM
3. Primative data types are just numbers or characters that can be compared
4. Complex data types called reference types that use relative addressing.
Classes relate to relative addressing. When using a class the memory ADDRESS
where the the information is stored in RAM is stored first.
5. Some common symbols
char data types use single quotes i.e. 'G'
== is equal or comparison
= is assignment
\n is a character
\t is a tab
! is NOT
6. newString tells the computer to find enough memory to store the information.Homework assignment 02-04-03
1. Resolve problems 9, 12, and 13 on page 52Class discussion
1. Java ia a free format programming language. This means the entire program
could be writtten on one line or can be written on multipul lines as long as
statements end with a semi colon (;).
2. /*Commenting out blocks of the program can be used to debug. By commenting
out sections of code and compiling it will tell you what section is causing the
program not to compile correctly. This paragraph is commented out.*/
3. A defined name is called an identifier.
4. Cast converts one type of variable to another.Homework assignment 02-06-03
1. Understand how to resolve all the problems at the end of chapter 2Class discussion
1. Review from Tuesday
2. How to map the public drive on GCC's server.
coming soon
3. The 3 basic parts of a program are:
Input variable definitions and what the user types into the program.
double p = 1000 //principal
double r = //rate
double t = 10 //time
Process How the problem is resolved.
X = p* r * t
Output The resolution to the problem.
System.out.println( );
4. Concatination is to joinHomework assignment 02-11-03
1. Resolve the Case Project on page 53Class discussion
1. An escape quote \"Gary\" is used to print a quote out within a
literal string.
2.More to come
Homework assignment 02-13-03
1. Resolve 10 of the 11 problems on handout. Due 02-20-03 Source code printed
out with screenshot (alt-printscreen) of each program and 1 cover sheet.Class discussion
1.Indirect referencing returns an address of where data is being stored.
2. new checks to see if there is enough space in RAM to store the data and reserves the space with an address of where the data will be stored.
3. null will be returned if enough space in RAM IS NOT found.
4. A method is a verb and can not be called without a noun in front of it.
i.e. get_input.readLineDoubleHomework assignment 02-18-03
1. Read pages 279-281, 285-300, 302-305, and anything else found about initClass discussion
1. TESTHomework assignment 02-20-03
1. Get SSH set up in class and at home so a connection to GCCs server can
be accomplished from home.Class discussion
1. Cover all documentation on SSH and make key to access server from
a computer outside the firewall.Homework assignment 02-25-03
1. Chapter 9 Applets
2. We will meet in D203 on Tuesday March 04-03Class discussion
1. In an applet init() replaces the main
2. In an applet everything is a string and must be converted.Homework assignment 02-27-03
1. Convert one od the 10 programs into an applet.
2. Learn basic Linux commands and practice working in Linux box.Class discussion
1. More to comeHomework assignment 03-04-03
1. Familiarize yourself with moving around in the Linux operating system.
2. Learn common Linux commands
3. Learn common commands for vim text editor
4. Common vim commands and tutorials can be found at VIM
Class discussion
1. Common Linux commands Other command pages can be found on
the resource page within this website.
2. Any time you want to get to your home directory you can type cp or cp~
3. In the Linux system you must mount and unmount external drives such
as a floppy or Zip drive. The command for this is
mount/mnt/zip and unmount/mnt/zip
4. To change your password on Linux yppasswdHomework assignment 03-06-03
1. Start reading chapter 3Class discussion
1.Relative and absolute paths
2. A relative path is related to where you are currently located in
your directory. a relative command would look something like this
cd ../whitegt/javafiles
3. An absolute path may look like this
cd /home/whitegt/javafiles
4. Calling methods outside the main from within the main.
More to come on this subject