1. Installing Java on a Home machine
For Windows Users: Download/Install: Go to
Accept License Agreement and then download the file named “jdk-8u51-windows-i586.exe”. Save the file to the desktop and run it.
The installer will install Java to: C:\Program Files\Java\jdk1.8.0_51\
Once the installer is finished, you must set your computer's path before Java will work correctly.

2. Installing Java on a Home machine (cont’d)
Setting the Path: Go to the Control Panel and double-click System Select the Advanced tab Click on the Environment Variables button Look under System Variables for "Path" Click on "Path" and then click edit Add the following to the end of the Path ; C:\Program Files\Java\jdk1.8.0_51\bin Click OK. Click the "New" button. For the variable name, type: CLASSPATH For the value, type: .; NOTE: The above value in words is period semicolon; it is not a misprint. Click OK. Exit out of all the open windows

3. Installing Java on a Home machine (cont’d)
To test if java is installed correctly: Open up a command prompt To do this click on Start and then Run Type in cmd.exe and click Ok Type java and hit enter If you see something like "command not found", then java is not installed correctly Otherwise you should see a list of options for running java

4. Developing a programming skill
Learning to program a computer
Training yourself to solve problems
in a very detailed and organized manner
You are already experienced in
Intuitive problem solving
Need to develop programming skill
Write a problem solution
IN terms of actions appropriate for a computer

5. Computer organization
Computer system
Hardware
physical, tangible pieces such as chips, wires, and so on
Useless without instructions to tell them what to do
Driven by a series of instructions, in other words programs
Software
Programs and the data those programs use
Intangible counterpart to the physical hardware components

6. Computer hardware Most computer have four major hardware parts
Central Processing Unit (CPU):
brain of the computer
executes individual commands of a program
Input/output devices
allow human beings to interact with a computer
Memory
stores programs and data while being processed by CPU

7. Computer hardware (cont’d)
Memory
Input devices
Output devices
CPU

8. What is programming Computers performs tasks
more efficiently, quickly, and accurately
than we could by hand
However, to be useful it must be programmed
Computer programming:
Devise a set of instructions
to be executed by a computer
In order to solve a given real world problem

9. How do we write a program?
It is a two phase process
Analysis and specification
General solution
(Algorithm)
Verify
Problem-Solving Phase
Concrete solution
(Program)
Test
Implementation Phase
Maintenance Phase

10. Algorithm implementation
JAVA code
Peter’s JAVA code
Algorithm
C++ code
Algorithm
Nell’s JAVA code
Ada code
John’s JAVA code
Algorithm translated into
different languages
Algorithm translated by
different people

11. Programming shortcut Problem Shortcut? Think first and code later
Problem Solving
Phase
(Algorithm)
Problem
Shortcut?
Implementation
Phase
(code)
Think first and code later

12. JAVA program execution
convert Java code to a form usable by computers
provided that in a computer instructions and data
are stored in the computer memories using binary codes
In a computer,
data represented by pulses of electricity
On circuit => ‘1’; Off circuit => ‘0’
Data in binary form => combination of enough 1s and 0s
Program execution means
translating data and instructions to patterns of 1s and 0s.

13. Programming language levels
Machine language
Primitive instruction built into each machine
Each type of CPU has its own language
Binary based instructions
=> tedious process and prone to error
Assembly language
Short English like words for commands and data
Tedious to use
Both are considered to be low level languages

14. Programming language levels (cont’d)
High level language
Expressed in English like phrases
Easier to read and write
High level Language
Assembly Language
Machine Language
a+b
ld [%fp-20] %o0
ld [%fp-20] %o1
add %o0, %o1

15. Program development Software tools involved
Editor: type a program and store in a file
Translation from high level into executable form
That translation may result in errors
You change the code to fix the problem
Execute the program and evaluate results
errors
errors
Edit and save
program
Translate
program
Execute
program

16. Compilers Translation into machine language Compiler:
Translates code in one language
to equivalent code in another one
Original code => source code,
Target language => particular machine language
Translate once and run whenever needed

17. Interpreters Translation into machine language Interpreter
similar to compiler with some differences
Interweaves the translation and execution
Parts of the source code
are translated and executed one at a time
Drawback:
Programs run more slowly,
as translation occurs during execution

18. JAVA translation and execution
The process
combines the use of a compiler and interpreter
Java source code -> Bytecode (Java compiler)
JAVA virtual machine reads bytecode and executes it
Difference between Bytecode and machine language
Bytecode is not tied to any particular processor type
It makes JAVA architecture neutral => portable

19. JAVA translation and execution (cont’d)
Source code
JAVA
bytecode
JAVA compiler
JAVA
interpreter
Bytecode
compiler
Machine
code