ITEC 120: Week 1

• Topics: Computer components: cpu, storage; information representation, compilation


• Chapter 1 Powerpoint Slides - Edited


• Binary prefixes


• Compiling with PFE

ITEC 120: Week 3

• QUIZ 2 on THURSDAY! Based on Homework 2

• Lab 5

• LAB QUIZ 1 on FRIDAY!

• Selected Topics from Chapter 2:
  • Parameter - provides information to a method
  • Primitive data types:
    • Integer types: byte, short, int, long
    • Floating point types: long, double
    • Other types: character, boolean
  • Expressions
    • Operators: +, -, *, /, %
    • Operator precedence
    • Expression trees
    • Assignment Operator precedence
    • Variables in assignment statements
  • Assignment using same variable on both sides
    • count = count + 1;
    • sum = sum + x;
  • Data Conversion
    • Widening/narrowing
    • Assignment Conversion
    • Promotion
    • Casting
    
    
  • increment and decrement operators
  • assignment operators


• Chapter 2 Powerpoint Slides - Edited


• Examples from Chapter 2


• To know for lab 5
• Submit to neelix (before lab, if possible)
• declarations, input, calculation(!), output

ITEC 120: Week 4

• Lab 7

• Lab 6

• Comments on quizzes
1. Constant needed
2. Constant style
3. Meaningful names
4. Indentation
5. Comment style
6. Stay ahead of the wave!
• Selected Topics from Chapter 3:
• Classes are (user defined) types
• Good style: class names are capitalized
• object.method() invokes a method
• Good style: method names not capitalized
• Methods do one of the following:
1. perform services (eg System.out.println();
2. return values to use in expressions and assignments (scan.nextInt();
• Aliases
• Assignment of reference variables copies pointer
• Can have two references to same object
• An alias
of a reference is another reference with a different name (eg two variables with same pointer value)
• Be careful with references: changes made via one alias are reflected for all aliases
• Garbage:
  • an object with no references to it
  • garbage is no longer accessible)
• Garbage collection
• Return garbage to runtime system for reuse
• automatic in java
• not automatic in C, C++, Ada, FORTRAN, COBOL
• automatic in some OO languages: Eiffel, smalltalk
• automatic in scripting languages like perl, php, vb(?)
• automatic in AI languages like LISP, PROLOG
• String class
• Special notation for creating Strings
• Strings are immutable
• Strings methods
• String characters indexed (starting at 0)
• Packages
• Libraries: tools for programmer
• Packages: organization tool for libraries
• organization tool for libraries
• package hierarchy: use dot notation (eg java.util.Scanner)
• Style: not capitalized
• Import: saves programmer typing
• packages random and class


• Method Declarations: parameters and return types


• Formatting Output


• Random Numbers




• Chapter 3 Powerpoint Slides


• Examples from Chapter 3

ITEC 120: Week 5

• QUIZ 3 on TUESDAY! Based on Homework 3. Topics:
  • String methods
  • Aliases
  • Reading method declarations and using methods (class Math)
  • Generating Random Numbers
  
  
• Program 1 due Tuesday midnight.

• LAB QUIZ 2 on FRIDAY!

• Lab 8

• Selected Topics from Chapter 3:
• Static Method calls and class Math


• Wrapper Classes


• Autoboxing (Warning: this violates type rules!)


• Enumerated types


• Selected Topics from Chapter 4:
• Wirth: Algorithms + Data Structures = Programs!


• RollingDice.java is a client of the Die class in Die.java (ie makes use of services)


• Objects have State and Behavior (and Identity)


• State - current value, defined by variables in class
• Behavior - actions object can take, defined by methods in class
• Identity - can create multiple instances of a given object
• State, Behavior, Identity for Students, Formatters, Die


• Class Die: State and behavior


• Fields: Instance data declared inside a class


• Fields: Each instance the fields


• Fields: different from variables declared inside methods

ITEC 120: Week 6

ITEC 120: Week 7

• Program 2 due next Monday (10/11)

• LAB QUIZ 3 next Wednesday (10/13)!

• Lab 11
• Lab 12
• Examples from Chapter 4


• Chapter 4 Powerpoint Slides


• Semester Calendar

ITEC 120: Week 8

• Program 2 due Monday (10/11)


• CLASS QUIZ Tuesday (10/12)!


• LAB QUIZ Wednesday (10/13)!


• Review of chapter 4: class Box, UML, encapsulation


• Chapter 5: If statements


• Flow of control: Statements are executed in sequence, unless directed otherwise
• Flow of control: Otherwise: method calls, conditionals (if, if-else, switch), loops


• An if statement hierarchically nests another statement inside it
• The nested statement is only executed if the if condition is true
• The nested statement can be another if statement
• Let your indentation reflect the program's hierarchy


• The condition is an expression that is true or false
• Equality operators (== and !=) compare two values for equality (can be used for numeric and boolean values and objects)
• Careful: don't confuse equality operator (ie ==) and assignment operator (ie =)
• For objects == compares the references, not the object fields
• For objects, .equals is usually better than ==
• For Strings, always use .equals since == can be misleading
• Relational operators determine the relative sizes of two values (can only be used for numeric values)
• Be careful of precedence of operators (eg 2+3 < 4+5)


• Examples from Chapter 5


• Chapter 5 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 9

• Tuesday:


• conditions to graduate and not graduate
• two ifs vs if else
• remembering a boolean result
• definite assignment
• statement blocks
• examples from book


• Thursday:
• Nested vs sequential if statements
• if else if else if else (eg grades)
• Equality of objects
• == compares references
• default version of .equals compares references
• specialized version of .equals compares fields


• Equality of Strings
• Use .equals
• == compares references (but strings can share references)


• Switch statements
• Similar to if else if else if else
• Use break


• Coding if else if else


• Examples: ...


• Chapter 5: Logical operators, if-else, block statements


• Logical operators combine two boolean values and produce another boolean value
• Contrast with
• Arithmetic operators combine 2 numbers and produce another number
• Relational operators compare two numeric values and produce another number


• Logical operator AND (ie &&)
• Result is true if both operands are true, false if either or both are false
• Truth table
• Example: graduation requirements: hours and gpa


• Logical operator OR (ie ||)
• Result is true if either operand is true, false if both are false
• Truth table
• Example: major and concentrations


• Logical operator NOT (ie !)
• Operates on a SINGLE value
• Unary operator vs binary operator (eg -3 + 4 shows both)
• Result is true if operand is false, and false if operand is true
• AKA logical negation and logical complement (not compliment)
• Truth table


• && and || are SHORT CIRCUIT operators: only evaluate second operand when required
• Example: if (x != 0 && 3/x > 5)


• DeMorgan's Law: !(a && b) == (!a || !b)
• DeMorgan's Law: !(a || b) == (!a && !b)
• if-else:
  • Use else to nest two statements
  • execute then part when condition is true
  • execute else part when condition is false
  • Examples:
  • Wages.java
  • CoinFlip.java
  • Coin.java
  • helps with definite assignment
  
  
• Block statements
  • A block statement is one or more statements enclosed in curly braces
  • Makes it possible to use several statements where one is required
  • Can be used as then and/or else parts
  • Guessing.java
  • Careful of indentation of multiline then or else parts
• Lab 14


• Lab 15


• Examples from Chapter 5


• Chapter 5 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 10

• Lab 16


• QUIZ 5 on THURSDAY! Based on Homework 5.


• Programming assignment 3 due midnight Monday 11/1/04.


• Loops


• Examples from Chapter 5


• Chapter 5 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 11

• Programming assignment 3 due midnight Monday 11/1/04.


• LAB QUIZ 4 on WEDNESDAY!


• Lab 18


• Examples from Chapter 6


• Chapter 6 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 12

• Last day to withdraw with a W: Friday of this week


• Exam on Monday!


• Program 4 due at noon on Friday of next week (before break)!


• Notes:


• The this reference
1. Within a class, this refers to the invoking object
2. When a method is called, this is a copy of the value of the invoking reference (eg when b.getArea() is called, the this reference gets a copy of the value of b)
3. Motivation 1: consistency of access (eg b.getArea(); this.getArea();)
4. Motivation 2: makes it possible to highlight the fact that a field in the current object is being accessed (eg return this.length * this.width;) or a method is being invoked on the current object (eg return this.getLength() * this.getWidth();)
5. Motivation 3: Allows access to a field that is hidden by a parameter with the same name
6. Motivation 4: Allows passing the invoking object as a parameter (eg myX.foo(this);). We will see examples of this later.


• More on Parameters
1. Formal and actual parameters
• Formal parameter: defined in the method declaration
• Actual parameter: used in the method call


2. Actions that occur on method call:
1. Formal parameters are allocated
2. The value of each actual parameter is copied into the corresponding formal parameter
3. When the method uses a parameter, it uses the copy, not the original


3. Effects of changes to formal parameters
1. Changes to primitive values are NEVER reflected in the actual parameter
2. Reference parameters can change the fields of the object pointed to
3. But reference parameters in the caller can NEVER be made to point to another object


• Overloading
1. When methods in a class have the same name and different signatures
2. Method signature: parameter number, type, and order
3. Signature does not include the method's return type and the parameter names
4. Example: Versions of method println are defined for ints, Strings, chars, ...
• Lab 19


• Lab 20


• Examples from Chapter 6


• Chapter 6 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 13

• Quiz on Chapter 6 on Thursday!


• Program 4 due at 4:00 p.m. noon on Friday of this week (before break)!


• Thanksgiving Break starts Saturday!


• Notes:


• Arrays! See the slides from the text.
• Array element initialization: Once an array is created, the elements have default initial values. This is similar to object fields having default initial values. The initial values for ints and doubles is 0 and 0.0, respectively.
• Arrays as parameters:

 
           public static void main(String[] args){
               int[] a = {11,22,33};
               int sum = sumIt(a);
               System.out.println(sum);
           }

           static int sumIt(int[] anArray){
               int theSum = 0;
               for (int i=0; i < anArray.length; i++)
                   theSum += anArray[i];
               return theSum;
           }
       



• Lab 21


• Examples from Chapter 7


• Chapter 7 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 14

• Thanksgiving Break, all week! Enjoy!

ITEC 120: Week 15

• Back to work!


• Lab Quiz 5 on arrays on Friday!


• Class quiz on arrays on Monday of next week (12/6/2004)!


• Programming Assignment 5 due midnight Wednesday 12/8/2004


• More on Arrays
• Arrays as parameters
• Arrays of Objects
• CD Collection Example


• Sorting, comparables and interfaces:
• Selection Sort (Section 9.4)


• Sorting arrays using Comparable Interface (Section 9.4)


• Interfaces (Sections 6.5 and 9.3)


• Lab 22


• Examples
• Examples from Chapter 7
• Examples from Chapter 9
• Examples from Chapter 6


• Slides from chapters
• Chapter 7 Powerpoint Slides
• Chapter 9 Powerpoint Slides
• Chapter 6 Powerpoint Slides


• Semester Calendar
  

ITEC 120: Week 16

• Class quiz on arrays on Monday!


• Inheritance


• Programming Assignment 5 due midnight Wednesday 12/8/2004


• Lab 23


• Sorting, comparables and interfaces:
• Selection Sort (Section 9.4)


• Sorting arrays using Comparable Interface (Section 9.4)


• Interfaces (Sections 6.5 and 9.3)


• Examples
• Examples from Chapter 8 (Inheritance)
• Examples from Chapter 9 (Interface Comparable)
• Examples from Chapter 6 (Interfaces)


• Slides from chapters
• Chapter 8 Powerpoint Slides (Inheritance)
• Chapter 9 Powerpoint Slides (Interface Comparable)
• Chapter 6 Powerpoint Slides (Comparable)


• Semester Calendar
  

ITEC 120: Week 17

• Final Exam: Thursday, December 16, 2004, 2:00 p.m.

• Final Exam Topics