Information Technology for Industrial Engineers 29 August ISE 582: Information Technology for Industrial Engineers

Transcription

1 ISE 582: Information Technology for Industrial Engineers University of Southern California Department of Industrial and Systems Engineering Lecture 2 HTML Forms, Introduction to JAVA Lecture 2 slides Homework 1 HTML Guides (hardcopy): Introduction to Tables Introduction to Forms READ: Handouts Winston & Narasimhan: Chapt 1-5 (pp 1-33) Lau: Chapt 1 (pp 1-8) 29 August 2001 Information Technology for IEs 2 1

2 Announcements Homework 1 is due a week from today TA Art Dhallin s office hours are Mon/Thu 10am-12pm, and by appointment Textbook: 12 copies are at bookstore (feel free to purchase online) 29 August 2001 Information Technology for IEs 3 The Agenda for Today Useful Stuff for Homeworks/Assignments HTML Forms: Making a Feedback Form Taking an Opinion Poll Introduction to Objects Programming in General Getting Started in JAVA 29 August 2001 Information Technology for IEs 4 2

3 Useful Stuff WS_FTP: file transfer Telnet / Putty: remote login am/putty/ Instructions on Modem Connections 29 August 2001 Information Technology for IEs 5 Emacs Edit a file: at the command prompt, type emacs <filename> Save a file: Quit: Open a file: CTRL-x CTRL-s CTRL-x CTRL-c CTRL-x CTRL-f Open 2 windows: CTRL-x 2 To toggle bet windows: CTRL-x o To get more help: CTRL-x CTRL-h 29 August 2001 Information Technology for IEs 6 3

4 HTML Forms <form action=url method=post></form> <input type=type> type=submit / reset type=button / checkbox / radio type=file / image / password <select name=? size=? multiple> <option> <option></select> 29 August 2001 Information Technology for IEs 7 At USC, Forms Help Public domain scripts, e.g.: Example: Feedback Form Example: Poster Vote, Online Poll 29 August 2001 Information Technology for IEs 8 4

5 Introduction to Objects Classes, Objects, Methods Unified Modeling Language (UML) UML Notation: Object Class UML Notation: Basic Relations 29 August 2001 Information Technology for IEs 9 Classes, Objects, Methods Object Instance Attributes (properties): associated data Operations: actions that change attributes Methods in JAVA Member functions in C++ Object Class Category or set of objects Share same attributes, operations and relationships to other objects 29 August 2001 Information Technology for IEs

6 Example: Object Class name age house claimtofame WIZARD changename( ) incrementage() calculatedob() Class name Attributes Operations 29 August 2001 Information Technology for IEs 11 Example: Object Instances w1: Wizard name = Albus Dumbledore age = 161 house = Gryffindor claimtofame = Defeated dark wizard Grindelwald w2: Wizard name = Harry Potter age = 21 house = Gryffindor claimtofame = Survived deadly curse by Voldemort 29 August 2001 Information Technology for IEs

7 Objects and older constructs Operation/ Method = function/procedure Object Instance = FAT variable containing multiple pieces of data and its own functions 29 August 2001 Information Technology for IEs 13 Unified Modeling Language Derived from previous modeling meth: 1994: Booch (Booch) 1992: OOSE (Jacobson) 1991: OMT (Rumbaugh) 1994: Booch and Rumbaugh of Rational Software Corporation began UML 1995: Jacobson joined their efforts 1997: UML submitted to OMG 29 August 2001 Information Technology for IEs

8 UML Notation: Object Class Convention: Attributes/operation names begin with lower-case characters Class and type names are capitalized Common Operations: Class name get*, set*, is* attributes:type Class name operations 29 August 2001 Information Technology for IEs 15 UML Notation: Basic Relations A A A 1 O..* B B C A class named A A is associated with B Number of allowable associated objects B is part of A (aggregation) C is subclass of B (inheritance) 29 August 2001 Information Technology for IEs

9 Ordering / Sorting, Navigation Polygon ISE * {ordered * {sorted Point One-way Navigation Student Bi-directional Navigation 29 August 2001 Information Technology for IEs 17 Programming in General Algorithms Pseudocode Reusable Components Testing and Debugging 29 August 2001 Information Technology for IEs

10 Algorithms and Pseudocode Hardest part in designing methods: coming up with a plan or strategy for carrying out the action Algorithm: set of instructions for solving a problem. So precise that even a dumb computer could follow the instructions and get the same results Pseudocode: an algorithm written in a mixture of English and some programming language 29 August 2001 Information Technology for IEs 19 Reusable Components Most programs combine already existing components Be sure to design classes so that they are reusable 29 August 2001 Information Technology for IEs

11 Testing and Debugging Syntax Error: a grammatical mistake Run-time Error: detected when program is run Logic Error: incorrect but legal 29 August 2001 Information Technology for IEs 21 Development Cycle Write or edit source code Compile source code Fix bugs that emerge during compilation Execute program Fix bugs that emerge during execution 29 August 2001 Information Technology for IEs

12 Getting Started in JAVA A Little JAVA History Compile and Execute a Simple Program Declare Variables Arithmetic Expressions, the Math Class Define a Simple Method 29 August 2001 Information Technology for IEs 23 JAVA: Definition 1. An island of Indonesia separated from Borneo by the Java Sea, an arm of the western Pacific Ocean. Center of an early Hindu Javanese civilization, Java was converted to Islam before the arrival of the Europeans (mainly the Dutch) in the late 16th century. 29 August 2001 Information Technology for IEs

13 JAVA: Definition 2. A trademark used for a programming language designed to develop applications, especially ones for the Internet, that can operate on different platforms. 3. n. Informal: Brewed coffee 29 August 2001 Information Technology for IEs 25 A Little JAVA History 1991: Programming Language for Home Appliances (Gosling) 1994: Coupled with HotJava webbrowser (Naughton and Payne) 1995: Netscape made browsers capable of running Java programs 29 August 2001 Information Technology for IEs

14 Source to Byte Code The Java compiler translates the class definitions and programs into byte code Byte code is executed by an interpreter, called a Java Virtual Machine 29 August 2001 Information Technology for IEs 27 Example: Compute Movie Rating Suppose script(6), acting(9), directing(8) To arrange for these scores to be totaled, define main inside class definition: accessibility public static void main (String argv[]) { class method, not instance method returns no value System.out.print( The rating of the movie is ); System.out.println( ); 29 August 2001 Information Technology for IEs

15 Example continued Embed method in a class definition accessibility class definition public class Demonstrate {... Explicit values are said to be literal Java is blank insensitive, but case sensitive 29 August 2001 Information Technology for IEs 29 Example: Compile and Execute At the command prompt: Type javac Demonstrate.java (this generates a file Demonstrate.class) Type java Demonstrate What will the output be? Data in this program is said to be Wired in or hard coded 29 August 2001 Information Technology for IEs

16 Declaring Variables in JAVA Identifiers are names of variables E.g. age, claimtofame, many$$$, no_way Variables are reserved chunks of memory that contain values. Type of variable determines how much memory is allocated to it. 29 August 2001 Information Technology for IEs 31 Some Variable Types char:2 bytes: characters byte,short,int,long: increasing:integers float,double: 4,8: floating point number OTHERS: boolean, string, arrays etc public class Demonstrate { public static void main (String argv[]) { int script, acting, direction 29 August 2001 Information Technology for IEs

17 COMMENTING YOUR CODE // This is a one-line comment /* This comment just goes on and on and on */ NOTE: no nesting of comments. 29 August 2001 Information Technology for IEs 33 ARITHMETIC EXPRESSIONS The usual operators: +, -, *, / Modulus: % (remainder in division) The usual precedence rules apply Mixing data types in expressions Casting an expression Original data type remains unchanged Assignment operates from R to L 29 August 2001 Information Technology for IEs

18 The Math Class public class Demonstrate { public static void main (String argv[]) { System.out.println( natural log of 10: + Math.log(10)); System.out.println( abs value of -10: + Math.abs(-10)); System.out.println( max of 2 and 3: + Math.max(2,3)); System.out.println( 5th power of 6: + Math.pow(6,5)); System.out.println( sqrt of 7: + Math.sqrt(7)); System.out.println( sine of 8 rad: + Math.sin(8)); System.out.println( Random no.(0,1): + Math.random()); 29 August 2001 Information Technology for IEs 35 EXERCISE Write a simple program to calculate Albus Dumbledore s birthdate. 29 August 2001 Information Technology for IEs

19 Defining a Simple Method ARGUMENTS public class Demonstrate { public static void main (String argv[]) { int script = 6, acting = 9, direction = 8; System.out.print( The rating of the movie is ); System.out.println(movieRating(script,acting,direction); public static int movierating (int s, int a, int d) { return s + a + d; PARAMETERS 29 August 2001 Information Technology for IEs 37 Defining Methods in Multiple Files public class Movie { public static int movierating (int s, int a, int d) { return s + a + d; public class Demonstrate { public static void main (String argv[]) { int s = 6, a = 9, d = 8; System.out.print( The rating of the movie is ); System.out.println(Movie.movieRating(s,a,d); 29 August 2001 Information Technology for IEs

20 Other Things to Know You can define more than one class in the same file To call a method in a different class, preface the method name with the class name and join with a dot. You can define multiple methods with the same name in the same class as long as they have different signatures (i.e. arrangement of parameter data types) 29 August 2001 Information Technology for IEs