1. Chapter 1: An Overview of Computers and Programming Languages
Java Programming:
Program Design Including Data Structures

2. Chapter Objectives Learn about different types of computers
Explore the hardware and software components of a computer system
Learn about the language of a computer
Learn about the evolution of programming languages
Examine high-level programming languages
Discover what a compiler is and what it does
Java Programming: Program Design Including Data Structures

3. Chapter Objectives (continued)
Examine a Java program
Examine how a Java program is processed
Become aware of the Internet and World Wide Web
Learn what an algorithm is and explore problem-solving techniques
Become aware of structured and object-oriented programming design methodologies
Java Programming: Program Design Including Data Structures

4. Introduction
Computers have greatly affected our daily lives— helping us complete many tasks
Computer programs (software) are designed specifically for each task
Software is created with programming languages
Java is an example of a programming language
Java Programming: Program Design Including Data Structures

5. An Overview of the History of Computers
1950s: Very large devices available to a select few
1960s: Large corporations owned computers
1970s: Computers got smaller and cheaper
1990s: Computers got cheaper and faster and were found in most homes
Java Programming: Program Design Including Data Structures

6. Elements of a Computer System
A computer has two components:
Hardware
Software
Java Programming: Program Design Including Data Structures

7. Hardware Components of a Computer
Central processing unit (CPU)
Main memory
Java Programming: Program Design Including Data Structures

8. Central Processing Unit
Control unit (CU)
Arithmetic logic unit (ALU)
Program counter (PC)
Instruction register (IR)
Java Programming: Program Design Including Data Structures

9. Hardware Components of a Computer
Java Programming: Program Design Including Data Structures

10. Main Memory Ordered sequence of cells (memory cells)
Directly connected to CPU
All programs must be brought into main memory before execution
When power is turned off, everything in main memory is lost
Java Programming: Program Design Including Data Structures

11. Main Memory with 100 Storage Cells
Java Programming: Program Design Including Data Structures

12. Secondary Storage Provides permanent storage for information
Examples of secondary storage:
Hard disks
Floppy disks
Zip disks
CD-ROMs
Tapes
Java Programming: Program Design Including Data Structures

13. Input Devices
Devices that feed data and computer programs into computers
Examples:
Keyboard
Mouse
Secondary storage
Java Programming: Program Design Including Data Structures

14. Output Devices Devices that the computer uses to display results
Examples:
Printer
Monitor
Secondary storage
Java Programming: Program Design Including Data Structures

15. Software
Software consists of programs written to perform specific tasks
Two types of programs:
System programs
Application programs
Java Programming: Program Design Including Data Structures

16. System Programs System programs control the computer
The operating system is first to load when you turn on a computer
Java Programming: Program Design Including Data Structures

17. Operating System (OS)
The OS monitors the overall activity of the computer and provides services
Example services:
Memory management
Input/output
Activities
Storage management
Java Programming: Program Design Including Data Structures

18. Application Programs Written using programming languages
Perform a specific task
Run by the OS
Example programs:
Word processors
Spreadsheets
Games
Java Programming: Program Design Including Data Structures

19. Language of a Computer
Machine language is the most basic language of a computer
A sequence of 0s and 1s
Every computer directly understands its own machine language
A bit is a binary digit, 0 or 1
A byte is a sequence of eight bits
Java Programming: Program Design Including Data Structures

20. Language of a Computer (continued)
Java Programming: Program Design Including Data Structures

21. Evolution of Programming Languages
Early computers programmed in machine language
Assembly languages were developed to make programmer’s job easier
In assembly language, an instruction is an easy-to-remember form called a mnemonic
Assembler: Translates assembly language instructions into machine language
Java Programming: Program Design Including Data Structures

22. Instructions in Assembly and Machine Languages
Java Programming: Program Design Including Data Structures

23. Instruction Set Architectures
This list is far from comprehensive as old architectures are abandoned and new ones invented on a continual basis.
ISAs commonly implemented in hardware
* Alpha AXP (DEC Alpha)
* ARM (Acorn RISC Machine) (Advanced RISC Machine now ARM Ltd)
* Burroughs B5000/B6000/B7000 series
* IA-64 (Itanium)
* MIPS
* Motorola 68k
* PA-RISC (HP Precision Architecture)
* IBM 700/7000 series
* IBM POWER
* PDP-11 (Digital Equipment Corporation)
* PowerPC
* SPARC
* SuperH
* System/360
* Tricore (Infineon)
* Transputer (STMicroelectronics)
* UNIVAC 1100/2200 series
* VAX (Digital Equipment Corporation)
* x86 (also known as IA-32) (Pentium, Athlon)
* x86-64 (also known as AMD64 and Intel 64)
* EISC (AE32K)
ISAs commonly implemented in software with hardware incarnations
* p-Code (UCSD p-System Version III on Western Digital Pascal MicroEngine)
* Java virtual machine (ARM Jazelle, PicoJava, JOP)
* FORTH
ISAs never implemented in hardware
* ALGOL object code
* SECD machine, a virtual machine used for some functional programming languages.
* MMIX, a teaching machine used in Donald Knuth's The Art of Computer Programming
* Z-machine, a virtual machine used for Infocom's text adventure games
Java Programming: Program Design Including Data Structures

24. Evolution of Programming Languages
High-level languages make programming easier
Closer to spoken languages
Examples:
Visual Basic, C#, J#
FORTRAN
COBOL
C/C++
Java
Java Programming: Program Design Including Data Structures

25. Evolution of Programming Languages
Java Programming: Program Design Including Data Structures

26. Evolution of Programming Languages (continued)
To run a Java program:
Java instructions need to be translated into an intermediate language called bytecode
The bytecode is interpreted into a particular machine language
Java Programming: Program Design Including Data Structures

27. Evolution of Programming Languages (continued)
Compiler: A program that translates a program written in a high-level language into the equivalent machine language
With Java, this machine language is the bytecode
Java Virtual Machine (JVM): A hypothetical computer developed to make Java programs machine independent
Java Programming: Program Design Including Data Structures

28. A Java Program public class HolaMundo { /* my first JAVA program */
public static void main(String[] argv)
System.out.println("Hola mundo"); }
Sample Run:
Hola mundo
Java Programming: Program Design Including Data Structures

29. A Java Program HolaMundo - ByteCode
Java Programming: Program Design Including Data Structures

30. A Java Program
Java Programming: Program Design Including Data Structures

31. A Java Program public class ASimpleJavaProgram {
public static void main(String[] args)
System.out.println("My first Java program");
System.out.println("The sum of 2 and 3 = " + 5);
System.out.println("7 + 8 = " + (7 + 8)); }
Sample Run:
My first Java program
The sum of 2 and 3 = 5
7 + 8 = 15
Java Programming: Program Design Including Data Structures

32. Processing a Java Program
Types of Java programs: applications and applets
Source program: Written in a high-level language
Loader: Transfers the compiled code (bytecode) into main memory
Interpreter: Reads and translates each bytecode instruction into machine language and then executes it
Java Programming: Program Design Including Data Structures

33. Processing a Java Program (continued)
Java Programming: Program Design Including Data Structures

34. Problem-Analysis-Coding-Execution Cycle
Algorithm: A step-by-step, problem-solving process in which a solution is arrived at in a finite amount of time (steps).
Java Programming: Program Design Including Data Structures

35. Problem-Solving Process
Analyze the problem: Outline solution requirements and design an algorithm
Implement the algorithm in a programming language (Java) and verify that the algorithm works
Maintain the program: Use and modify if the problem domain changes
Java Programming: Program Design Including Data Structures

36. Problem-Analysis-Coding-Execution Cycle
Java Programming: Program Design Including Data Structures

37. Programming Methodologies
Two basic approaches to programming design:
Structured design
Object-oriented design
Java Programming: Program Design Including Data Structures

38. Structured Design A problem is divided into smaller sub-problems
Each sub-problem is solved
The solutions of all sub-problems are combined to solve the problem
Java Programming: Program Design Including Data Structures

39. Object-Oriented Design (OOD)
OOD: program is a collection of interacting objects
An object consists of data and operations
Steps in OOD:
Identify objects
Form the basis of the solution
Determine how these objects interact
Java Programming: Program Design Including Data Structures

40. Chapter Summary
A computer system is made up of hardware and software components
Computers understand machine language; it is easiest for programmers to write in high-level languages
A compiler translates high-level language into machine language
The Java steps required to execute a program are edit, compile, load, and execute
Java Programming: Program Design Including Data Structures

41. Chapter Summary (continued)
Algorithm: step-by-step, problem-solving process. Solution is arrived at in a finite amount of time
The three steps of the problem-solving process
Analyze the problem and design an algorithm
Implement the algorithm in a programming language
Maintain the program
Two approaches to programming design are structured design and object-oriented design
Java Programming: Program Design Including Data Structures