Chapter 1 & 2: Software Basics

(AP Computer Science Standard: II Program Implementation, III Program Analysis, VI Computing in Context)

First Day

Introduction - Hand out syllabus

1. Use console output (System.out.println)

Programming Assignment 1: Write a program that outputs "Hello World" to the screen.

2. Define the term debugging.
3. Define compiling error and describe a way to cause one.

Deliberately delete a ";" from the above program and note the error message. Deliberately alter other elements of the program to see what happens

Second Day

4. Explain what compilers and interpreters do and why compiled code generally runs faster.
5. Describe how Java's source code is compiled to byte code and then interpreted by the Java virtual machine work together.
6. Give examples of different operating systems and explain why the Java virtual machine is needed.
7. Define encapsulation and information hiding

Programming Assignment 2: Write a program that inputs (your name) and (your age) on the command line and outputs "Hello (your name) you are (your age) years old".

8. Define run-time error and describe a way to cause one. (Usually throws an exception.)

Deliberately cause a run time error in  the above program and note what happens.

9. Define the term iteration and describe a way to do it--example: pounding a nail, "for" loop

Programming Assignment 3: Modify Programming Assignment 2 with a "for loop" so that the message repeats itself 10 times. once the program is running, modify it so that it has an infinite loop and see what happens when you run it.

Sample code:

for (int x = 0; x < 10; x ++) {

    //Lines of code

}

10. Define logic error and describe a way to cause one.
11. Be aware that while a program can branch to a different part of the code or go round-and-round in a loop, it otherwise executes sequentially from the top to the bottom for a given method.
12. Describe one of the key strategies in the creation of complex software: functional decomposition ( breaking down an overwhelmingly complex task into smaller doable tasks). Note: Creating a a software project of even a few hundred lines of code rapidly becomes complex if not overwhelming. The key to success is to take baby steps.
13. Complete the first chapter of the AP Computer science case study GridWorld.

• Go to the College board site and download the... Student Manual (.pdf/630KB)
• Download the................................................................. Code (.zip/238KB)
• Download and follow the............................................. Installation Guide (.pdf/172KB) for Bluej

Assignments: The below assignments are to be completed within the first 10 days of school.

Homefun (summative/formative assessment):

GridWorld: Read Section 1; Do exercises 1-4. Note: you will not understand all of the terminology. Don't worry: your not supposed to. However, you'll find that if you don't let the jargon bother you, you can muddle through. In programming, muddling is a highly valued art.

Programming Assignment 4: Write a program which receives three input characters via command line input and outputs your printed initials in large size (at least 2 inches high) using the 3 input characters stored in string variables. Note: you need to write the initials on graph paper in order to know how many spaces to put between the string variables.

Example 1: Input: "T", "K", "R" Output: T T T T T   K     K   R R R R     T       K   K     R     R     T       K K       R R R R     T       K   K     R   R       T       K     K   R     R

Example 2: Input: "X", "Y", "Z" Output: X X X X X   Y     Y   Z Z Z Z     X       Y   Y     Z     Z     X       Y Y       Z Z Z Z     X       Y   Y     Z   Z       X       Y     Y   Z     Z

Read Sections: 2.1 to 2.3  

Chapter 1 & 2 (continued): Hardware Basics

(AP Computer Science Standard: VI Computing in Context)

14. Define the terms:

• bit--a binary digit
• byte--8 bits
• kilobyte--old = 2¹⁰, new = 1,000 bytes
• megabyte--old = 2²⁰, new = 1,000,000 bytes
• gigabyte--old = 2³⁰, new = 1,000,000,000 bytes

15. State the basic types of gates and give logic tables for each. http://scitec.uwichill.edu.bb/cmp/online/P10F/logic_gates2.htm

• not
• and
• or
• xor (can be made from the 3 gates shown above)

3 Person Group Assignment:

1. Create a digital circuit using gates that describes an activity (must use both "and" as well as "or" gates, 5 gates minimum).
2. Create an xor gate from "not", "and" and "or" gates.

16. Correctly identify and describe the functions of the following components.
• CPU
• RAM--primary memory, usually volatile
• Hard drive--secondary memory, non volatile
• Power Supply and its highest output voltage (12 v)--static charge must be above 10,000 volts (more than enough to "zap" electronics) to be felt
• Mother board/bus--how the CPU communicates with the computer's parts
• Video Card/monitor--how the computer communicates with you
• USB, Parallel, and Serial ports--how the computer communicates with peripherals, such as printers
• Network card--how the computer communicates with other computers

 

17. Describe the function of ROM and the BIOS.
18. Describe the function of a UPS (uninterrupted power supply, battery back up).
19. Name the 2 most common I/O devices. (keyboard, monitor)
20. Compare single user computer systems with Networks.

• stand-alone applications (single user)--word processors, spread sheets, etc.
• information sharing and communication--various mark up languages such as html (used on web pages), 
• distributed software--applets (use java language), java scripts (not java!), server side software, etc
• cluster computing--Beowulf systems, SETI

Read Sections: 1.1 to 1.4

Summative Assessment: Test Chap 1 & 2 Objectives 1-20

Chapter 1 & 2 (continued): How Information is Represented

1. Describe the following number systems: binary, decimal, and hexadecimal (see How to Count to 1,023 on Your Fingers).
2. Convert binary to decimal numbers.
3. Convert binary to hexadecimal numbers.  (see Hex Headquarters)
4. Convert hexadecimal to binary.
5. Convert hexadecimal to decimal numbers.
6. State how characters are represented inside computers and give the name of the 2 types of code.

• Write a program that converts a lower case character to upper and vice versa.
• State which comes first upper or lower case numbers.

Code Type	Bytes	Possible Characters
ASCII	1	256
Unicode (used in Java)	2	65,536

8. Describe how colors are commonly represented
9. Given a quantity of bits specify the largest number which can be represented.
10. Given a number of bits specify the largest number of objects or colors which can be specified.

Read Sections: 1.5 to 1.7

 

Homefun (summative/formative assessment):

Complete the Number Conversion and Unicode worksheet

Chapter 1 & 2 (continued): Software Design Basics

(AP Computer Science Standard: I Object-Oriented Program Design)

11. Use the two major computer program development tools.

• Pseudo code
• Flow Charts--use PowerPoint

12. Use a flow chart to represent algorithms containing a loop

• multiplication using only addition-- x∙y → Input x and y. Set product = 0 and add x to it y times. Output product.
• division using only subtraction-- x/y → Input x and y. Set counter = 0. Subtract y from x and add one to counter. Repeat the process until x < 0.  The quotient = (final counter value) - 1. The remainder = ( final x value) + y. Output the quotient and remainder.

13. Contrast procedural and object oriented programming. (Note: Java is object oriented.)

15. Describe top-down design.
16. Describe key strategies in the test phase.

• isolation testing--classes and libraries are tested separately
• boundary condition testing--boundaries are identified and used for generating test data.
• integration testing--all of the software's components are combined and tested as a unit

17. State the type of program used for delivering Java programs over the internet.
18. Write a simple applet. (See AppletDemo Code. Run AppletDemo)

Read Chap. 2

Homefun (summative/formative assessment):

Exercises 1, 6, p. 38

Use a flow chart to represent algorithms containing a loop

• multiplication using only addition
• division using only subtraction

Programming Assignments:

• Exercises 14, (15 &16) in same program
• Write a really cool applet that moves three or more different types of graphic elements around the screen while changing their color and size. Output a stationary title for the applet in the center of the screen so that it is never obscured by the moving elements. The elements are to look like they move under the writing. Use a timer to control the speed of the animation.

Summative Assessment: Test Chap 1 & 2 Objectives 1-18--come prepared to write an applet on paper

1. Correctly use the following terms and be able to identify and use them in a program:

• API (Applications Programming Interface)--the ultimate source of information for reusable Java code.

• packages

• fully-qualified name - Library.package.class example: javax.swing.JButton (means JButton class)

• wild card - *

• instance

• object

• methods--the name of the method is always followed by a set of parentheses. example: calculateCost ( )

• instance methods When used by a different class it is called with an instance of its home class, example: bob.getsOlder ( ). bob is an instance or object of the class containing the getsOlder method.

• Static methods declared static in the method's 1st line of code. When used by a different class it is called with name of its home class, example Math.cos (5.9). Math is the class name. cos ( ) is a method inside the Math class. 5.9 is a double being passed to the cos method as an argument.

• parameters--give data types. Parameters are contained in method's header and specify the arguments to be used when calling a method. example: computeTax (double income, int age). income and age are both parameters.

• arguments--used when calling a method. example: computeTax (dollars, years). dollars and years are both arguments. Note: the data type of the argument must mach that of the parameter, but the name does not need to match.

• constructor (called with new operator when the object is created and allocated RAM) Must have the same name as the class.

• field (primitives or objects) declared at the top of the class

• static--static methods & fields called with the name of their class

• event

• listener

• interface--uses the implements keyword, often used for adding listeners.

• classes--their names are always capitalized

 

Programming Assignment (summative/formative assessment): Complete the Pumpkin Project as specified in the Farm class using the Pumpkin class.

Inheritance

3. Explain the "has-a" relationship. (Used for defining fields)

client, characteristic, or component relationship examples: A car has a motor. A store has a customer. A girl has a name. A class has a field.

4. Use "super" to call public methods of a super class from within a subclass.

super.calculateHours ( double starTime, double stopTime);

5. Be aware that private fields in a superclass cannot be accessed in subclasses.

6. Access a superclass's protected fields from a subclass by calling a get method for the field.

example : super.getWeight ( );  // returns the value of the protected

                                                 // weight field found in the 

                                          // superclass

7. Explain the term "primitive data types" and give examples.

examples: int, char, double

8. Name four classes contained in the java.lang package which is automatically imported into your java programs.

• System

• Math

• Object

• String

 

Read Chap. 3; Computational Thinking

 

Homefun (summative/formative assessment):

1. Write brief definitions for the above terms in objectives 1 and 2. Use the textbook and the Sun Developer Network Glossary.

    

2. Next find a program(s) with examples of each and identify them. You may use programs from the book, the internet, or ones you've written yourself. You may work as a group on part 2.

Programming Assignment: Exercise 9, 10, 12

Programming Assignment: Write an applet with a Student class, a School class and a Grades interface. The student class will have fields for name, test1, test2, and average grade. It's constructor will have parameters for initializing all the fields except average grade. The grades interface will have a method for calculating average grades. The student class will make use of the method that calculates average grade from the grades interface. The school is to have 3 students created in the school class and is to output all the school's information in a table as follow shown in the following example:

Name          Test 1       Test 2          Average Grade

Bob              50            100              75

Jane             90            100              95

Martha          80            90                85

 

Summative Assessment: Test Chap 3 Objectives 1- 8

Relevance: Knowledge of object oriented programs (OOPs) is a highly useful employment skill The degree breakdown for computer/math scientists

 

Essential Question: How does an algorithm compare to a mathematical model in physics or engineering?

1. Define the term algorithm.
2. Correctly use recursion. Read the Barron's book write up on recursion. Click here for a simple example of recursion. Relevance: If you can do recursions you can learn to do anything in Comp Sci.
   • Must call itself within the method
   • Must alter one or more of its arguments each time it calls itself.

   • Must have a means of stopping itself based on the modified argument(s)

   • Stores calculated values in a stack and evaluates them after the recursion stops.

Programming Assignment: Write a program that inputs an integer n using command line input and uses it to calculate n factorial using recursion.

 

Programming Assignment: Write an application that finds and outputs Pi using recursion and the following series: Click here for 3 examples of recursion.

(Pi ²)/6 = 1 + 1/2² + 1/3² + ... + 1/n²

Input the number of times the recursion should run using command line input.

3. Determine the number of iterations a given recursion will have.
4. Define list in abstract terms. an abstract data structure that implements an ordered collection of values, where the same value may occur more than once. The simplest form of list is an array.

• items numbered
• method for accessing the i ^th item is defined

5. Define traversal.
The process of visiting (examining and/or updating) each node or item in a list.
6. Compare sequential to binary search.

   Note: O(----) as shown below is called big O notation and indicates how run time will increase for as the amount of data items = n increases.

 

Read Chap. 4; Algorithms Should Mind Your Business, How To Think: Algorithmic Thinking, Read the Recursion section of the Barron's book. Read and study yet another Mr. Rogers' recursion example.

 

1) Exercises 1,  7, 9,
2) Based on the reading assignments, write a 1/2 to one page paper explaining what algorithmic thinking is and how it differs from mathematical thinking.

1. Correctly use the three forms of comments:

• // Single line comment

• /* One or more lines of comments*/

• /** Javadoc comments*/

2. Identify reserved words (p. 107).

3. Correctly use the naming conventions for classes, methods, and fields.

• Capitalize the first letter of classes but not methods or fields.

• The first character must be a letter & have no spaces in it.

• Names can include letters, numbers or the underscore_.

• Names should be descriptive.

• Method names = verbs, field = nouns

• Constants use all capitals.

4. Correctly indent programs.

Homefun (summative/formative assessment):

Read Chap. 5; Princeton professor foresees computer science revolution

Exercises 3, 4, 5, 7, 8, 10

Programming Assignment: Lab 5.6

 

Relevance: A program won't run without proper syntax. Proper style makes the code readable so that it can be modified and maintained.

 

Essential Question: Why did you learn to find remainders in grade school instead of going straight to long division ?

5. Understand the meaning and use of the equal sign in Java.

• Can have only one field or variable on the left side

• Means "replaced by", not equals

6. Correctly declare fields and local variables.

7. Correctly initialize fields, local variable, and parameters.

8. State the default values used for initializing fields.

• numeric types: 0

• objects: null

9. State the default value used for initializing local variables. (there isn't one)

10. State the eight types of primitive data types and their sizes in bytes. (p. 129)

11. Explain why the largest size of an integer or long variable can be a major issue.

12. Explain the limitations of precision on floating point data types and why these limitations can produce round-off errors.

13. State the primitive data types which do not have a true zero and explain why this can be a problem.

14. Correctly Use:

• literal constant - letters in single quotes and numbers

• symbolic constant - declared and initialized using final

• escape sequences (p.131, \n newline, \t tab, \\slash, etc.)

15. Understand the term scope (p. 133). Note: the concept of scope is incredibly important to programming in Java. You must consider it whenever you create a variable. As a matter of style, variables should be declared at the top limit of their scope.

• inside the { } of a class

• inside the { } of a method

• inside the { } of a loop, if, else statement, or any other set of {}

16. Correctly convert numbers and objects into strings and explain why objects need special attention. (An object may have multiple variables or fields of different data types associated with them, hence the output has to be defined in order to understand how it should be done.)

• Concatenate to an empty string. Example: System.out.print ("" + 6);

• Use toString method for converting objects to strings (This method outputs the class name and memory location. To output something more meaningful it has to be overridden.)

Homefun (summative/formative assessment): read Sections 6.1 to 6.5; Exercises 1- 7 p.146-147

17. Use literal constants as either int or doubles (Example: int: 2, double: 2.0).

18. Correctly use the order of operation for arithmetic.

    1. parentheses

    2. division, multiplication, modulus

    3. addition, subtraction

19. Perform division using integers and doubles.

Note: integer division truncates the decimal portion of a number. It does NOT round numbers. Mixed division of integers and doubles upgrades the answer to a double (this is called autoboxing).

Examples:

division of integers: 1 / 2       yields 0

division of doubles: 1.0 / 2.0 yields 0.5

mixed division:         1 / 2.0    yields 0.5,  1.0 / 2    yields 0.5  

 

17. Truncate and round numbers using integer division.

Examples:

1/2 rounded to nearest whole number

((1*10) / 2 + 5) / 10  yields 1

 

y/x  rounded to nearest whole number

((y*10) / x + 5) / 10

20. Cast variables.

Example:

int a, b;

double c;

c = (double) a / (double) b;

Correctly use various arithmetic operators including: modulus (%) returns remainder: 1 = 5 % 2 compound assignment operators (/=, +=, -=, *=, %=) increment/decrement (y++, ++y, y--, --y)

Modulus Examples 1 = 1 % 3 2 = 2 % 3 0 = 3 % 3 1 = 4 % 3 2 = 5 % 3 0 = 6 % 3

 

Homefun (summative/formative assessment): Read Sections 6.6 to 6.10; Exercises 8, 10, 11 p.147-148

Programming Assignment: Lab 6.10, Exercises 12, 13 p.148

 

Programming Assignment: Write a program which uses command line input to input a single dimension in centimeters. Use this dimension to calculate and output the surface area and volume of a cube, sphere, and cylinder along with the correct units. The radius and height of the cylinder are equal to the dimension. Use a separate method for each calculation.

Relevance: Handling massive numbers of transactions involving money without losing anything to rounding errors is a major issue for international finance and businesses.

 

Essential Question: How does a progressive income tax system work and is it a good idea?

Tax code program:

Input: Using the command line input income in dollars. (This needs to be changed to cents inside the program.)

Output:

• Taxable income in dollars

• Tax due in dollars (round tenths of cents upward)

• Nominal tax rate in % of income

NTR = (taxDue) / (income) *100

Description: The program will round any tenths of a cent upward. "If" statements are not allowed. The program will use only algorithms to calculate taxes. It will use the following progressive tax table:

 

Income ($)	Tax Rate	Comments
0 to 19,999.99	00 %	This part of income is never taxed
20,000 to 29,999.99	25 %	Only income above $19,999.99 is taxed at 25%
30,000 +	35 %	Only Income above $29,999.99 is taxed at 35%. Note this is an additional 10% above the 25% tax that kicks in at $29,999.99.

 

Homefun (summative/formative assessment):

Practice Test

Summative Assessment: Test Chap 5 & 6 Objectives 1-22