40
Welcome to CMPE003 Personal Computer Concepts: Hardware and Software Winter 2003 UC Santa Cruz Instructor: Guy Cox
Welcome to CMPE003 Personal Computer Concepts: Hardware and Software
Winter 2003UC Santa Cruz
Instructor: Guy Cox
January 23, 2003 2
Assignments
Assignment #6 – DUE TODAY Due March 12, 2003
Spreadsheets – (MS Excel) Generate a monthly budget spreadsheet
January 23, 2003 3
Final Project
Due no later than March 19, 2003 You can turn in earlier..
Power Point presentation 4 pages Extra points for special effects, animations
Up load to your CATS account and write file location on your printout
http://www.soe.ucsc.edu/classes/cmpe003/Winter03/finalproject.html
Programming Languages: Telling the Computers What to Do
Chapter 16
January 23, 2003 5
Objectives
Describe what programmers do and do not do Explain how programmers define a problem,
plan the solution and then code, test, and document the program
List and describe the levels of programming languages – machine, assembly, high level, very high level, and natural
Describe the major programming languages in use today
Explain the concepts of object-oriented programming
January 23, 2003 6
Program
Set of instructions written in a programming language that tells the computer what to do
January 23, 2003 7
Programmers
Prepare instructions that make up the program Run the instructions to see if they produce the
correct results Make corrections Document the program Interact with
Users Managers Systems analysts
Coordinate with other programmers to build a complete system
January 23, 2003 8
The Programming Process
Defining the problem Planning the solution Coding the program Testing the program Documenting the program
January 23, 2003 9
The Programming Process: Defining the Problem
What is the input What output do you expect How do you get from the input to the
output
January 23, 2003 10
The Programming Process: Planning the Solution
Algorithms Detailed solutions to a given problem
Sorting records, adding sums of numbers, etc.. Design tools
Flowchart Pseudocode
Has logic structure, but no command syntax Desk-checking
Personal code design walk through Peer Reviews
“Code walk through”/structured walk through
January 23, 2003 11
The Programming Process: Planning the Solution
Accept series of numbers and display the average
January 23, 2003 12
The Programming Process: Coding the Program
Translate algorithm into a formal programming language
Within syntax of the language How to key in the statements?
Text editor Programming environment
Interactive Development Environment (IDE)
January 23, 2003 13
The Programming Process: Testing the Program
Translation – compiler Translates from source module into object
module Detects syntax errors
Link – linkage editor (linker) Combines object module with libraries to create
load module Finds undefined external references
Debugging Run using data that tests all statements Logic errors
January 23, 2003 14
The Programming Process: Testing the Program
January 23, 2003 15
The Programming Process: Documenting the Program
Performed throughout the development Material generated during each step
Problem definitions Program plan Comments within source code Testing procedures Narrative Layouts of input and output Program listing
January 23, 2003 16
Choosing a Language
Choice made for you What is available? Required interface
What do you know best? Which language lends itself to the
problem to be solved?
January 23, 2003 17
Language Generations
Low levels closer to binary High levels closer to human code Five Generations:
Procedural Languages Machine language Assembly language High-level language – 3GL
Nonprocedural Languages Very high-level language – 4GL Natural language – 5GL
January 23, 2003 18
Machine Language
Written in strings of 0 and 1 Displayed as hexadecimal
Only language the computer understands
All other programming languages are translated to machine language
Computer dependent
January 23, 2003 19
Assembly Language
Mnemonic codes Add, sub, tst, jmp…
Names for memory locations Computer dependent Assembler translates from Assembly to
machine language
January 23, 2003 20
3GL: High-Level Languages
1960s Languages designed for specific types
of problems and used syntax familiar to the people in that field FORTRAN: (FORmula TRANslator)
Math COBOL: (COmmon Business Oriented
Language) Business
Compile translates from high-level language to machine language
January 23, 2003 21
4GL: Very High-Level Languages
Programmer specifies the desired results; the language develops the solution
Ten times more productive with a 4GL than a procedural language
Query Languages Retrieve information from databases Easy to learn and use
January 23, 2003 22
5GL: Natural Languages
Resemble natural or spoken English
Translates human instructions into code the computer can execute
Commonly used by non-programmers to access databases
January 23, 2003 23
Third Generation Languages: Traditional Programming
Describe data Describe procedures or operations on
that data Data and procedures are separate
January 23, 2003 24
Third Generation Languages
FORTRAN 1954 Represent complex mathematical formulas C/C++ has replaced FORTRAN
COBOL 1959 Business Large complex data files Formatted business reports
January 23, 2003 25
Average a list of numbers
Accept series of numbers and display the average
January 23, 2003 26
Third Generation Languages
FORTRAN
January 23, 2003 27
Third Generation Languages
COBOL
January 23, 2003 28
Third Generation Languages
BASIC (Beginners All-purpose Symbolic Instruction Code) 1965 Popularity grew with PC popularity (1970s) Easy to learn Used little memory Bill Gates beginnings.. MS Basic
RPG 1965 Report generation – quickly creates complex
reports
January 23, 2003 29
Third Generation Languages
BASIC
January 23, 2003 30
Third Generation Languages MS Visual Basic
1987 Create complex user interfaces Uses standard Windows features Event-driven – user controls the program
C 1972 Efficient code – the language of UNIX Portability
C++ Enhancement of C (Object Oriented)
January 23, 2003 31
Third Generation Languages
C++
January 23, 2003 32
OOP: Object-Oriented Programming
Object Self-contained unit of data and instructions Includes
Related facts (data) Related functions (instructions to act on that data)
Example Object: cat Data: feet, nose, fur, tail Functions: eat, purr, scratch, walk Cat: Kitty, Tabby
January 23, 2003 33
OOP: Object-Oriented Programming
Encapsulation – describes the objects self- containment
Attributes – the facts that describe the object Methods / operations – the instructions that tell
the object what to do Instance – one occurrence of an object Messages – activate methods
Polymorphism
Example: A ‘walk’ message causes Kitty to move (in a cat-like way)
January 23, 2003 34
OOP: Object-Oriented Programming
Class – defines characteristics unique to all objects of that class
Inheritance – Objects of a class automatically posses all of the characteristics of the class from which it was derived
Subclass – inherits characteristics from class and defines additional characteristics that are unique
Instance – actual occurrence of an object
January 23, 2003 35
ExampleClass: Boat
Subclass: Canoe
Subclass: Powerboat
Subclass: Sailboat
Instance: Chardonnay II
OOP: Object-Oriented Programming
January 23, 2003 36
OOP: Object-Oriented Programming
Using Objects in BusinessClass: CustomerSubclass: Retail or WholesaleInstance: John Smith
Retail and Wholesale customers automatically inherit customer address since it is part of the Customer class
January 23, 2003 37
OOP: Object-Oriented Programming
Languages C++
Can write both structured and object-oriented code Visual Basic
Rudimentary features of object-oriented language
January 23, 2003 38
Third Generation Languages
Java Cross-platform Java Virtual Machine (JVM)
Sits on top of computer’s regular platform Translates compiled Java code into instructions for
the specific platform Applets
January 23, 2003 39
Learning to Program
Enroll in courses Learn logic as well as language syntax
Read books, articles Use tutorials View Sample code Write code (start small)
Enjoy
January 23, 2003 40
