Review Review Review

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Review ReviewReview
2
Concepts

• Comments definition, example, different types of
  comments
• Class definition, example
• Object definition, example
• Data type
• Byte, short, int, long, float, double
• Char, boolean
• String

3
Concepts

• Assignment statement
• Boolean expressions
• Identifiers, constants
• Commands
• If
• Switch
• Do/While, While, and For

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Concepts

• File extension .java, .class
• Compile
• Textpad Compile Java and Run java
• DOS javac and java

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Project 1 (Section 01)

• Average 93.14 (35 students submitted)

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Project 1 (Section 2)

• Average 97 (only 28 students submitted)

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Lab section
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Homework 1 (Section 01)

• Avg 84.3. Max 99.

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Homework 1 (Section 02)

• Avg 88, Max 100

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Rules for Midterm exam

• Student ID is required
• Dont
• Leave the exam room after the exam is distributed
• Use cell phone or computers (PC)
• Talk with each other during the exam
• Limit of questions you can ask teacher during
  exam time. If you ask more than two questions,
  you will have some points off taken from your
  exam.

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Answers to Homework 1

• 1. In general, commands to compile and execute a
  java program are
• a. compile and run
• b. compile and link
• c. javac and java
• d. java and link

This is the only answer accepted if this question
is asked in another exam
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Homework 1 - Answer

• 2. All Java program must have this method to run
• a. hello()
• b. start()
• c. main()
• d. method()

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Homework 1

• 3. Which of the following is not mandatory in
  variable declaration
• a. a semicolon
• b. an assignment
• c. a variable name
• d. a data type

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Homework1

• 4. You store java source code files with
  following extension?
• a. .java
• b. .class
• c. .src
• d. .javadoc

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Homework1

• 5. A single line comment in Java starts with
• a.
• b.
• c. ,
• d. //
• e. none of the above

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Homework1

• 6. Java language is case sensitive
• a. True
• b. False

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Homework1

• 7. As long as a computer has a Java Virtual
  Machine, the same program written in the Java
  programming language can run on any computer
• a. True
• b. False

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Homework1

• 8. Which of the following is an invalid
  identifier?
• a. one
• b. Two
• c. _3Four
• d. 4Five

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Homework1

• 9. Which of the following is an invalid variable
  declaration?
• a. String inputStr
• b. int i0
• c. boolean flag true
• d. double, int, j0

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Homework1

• 10. Assuming the following declarations are
  executed in sequence, why are the second and the
  third declarations invalid?
• int a,b
• double a
• double b
• a. Both a and b are invalid identifiers.
• b. Variable a has been declared
• c. Variable b has been declared
• d. Both variables a and b have been declared in
  the first declaration

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Homework1

• 11. The __new_____operator is used to create a
  new object

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Homework 1

• 12. Identifiers may not start with a ___number
  (digit)________ or contain__special/(non-alpha-num
  eric)_____characters, other than the underscore
  or the dollar sign

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Homework 1

• 13. char data type represents individual
  _character______

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Homework 1

• 14. Text data can be stored in _String__objects

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Homework 1

• 15. Constants __can not be (never be, are
  not)__changed during program execution

26
Homework 1

• 16. Boolean expressions are built by use of
  _relational___operators and _boolean__________oper
  ators

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Homework 1

• 17. Every variable that we use in a Java program
  must be _declared/defined__________

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Homework 1

• 18. A Java program is composed of one or more
  ___classes__

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Homework 1

• 20. int a b
• cant be used in variable declaration

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Homework 1

• 21.
• double monthlyInterestRate
• if (monthlyInterestRate gt 0.08)
  (monthlyInterestRate lt 0.5 )
• System.out.println(Interest rate is invalid)
• System.exit(1)
• () is needed or remove )( before and after
• should be take out
• No value has been initialized for
  monthlyInterestRate

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Homework 1

• 22. char userChoicel
• if (userChoice s)
• System.out.print( Drop small cup into
  position) (1) Missing
• else System.out.println( Drop large cup into
  position)
• else System.exit(-1)

2. should be inserted here
Else should be taken out
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Homework 1

• 23. String choice5
• switch(choice)
• case 4 System.out.println( Right branch)
  break
• default System.out.println( Default branch)
  break
• 1. Switch doesnt support String data type. It
  must be char or int(bytes,short,int)

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Homework 1

• 24. int sum0
• for (int i0, ilt 100)
• sum i
• 1 int i0, this comma should be semicolon
• 2. Missing post body update (increment or
  decrement)
• 3. semicolon after 100) should be taken out

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Homework 1

• 25. int x,y
• x-10
• y-20
• if ( ygt0 xlt y)
• System.out.println(" The output is "(xy))
• else
• System.out.println(" The output is "(x-y))
• The output is 10
• (Because -10-(-20) -1020 10)

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Homework 1

• 26. int count0, sum0
• while (count lt 10)
• sum count
• count3
• System.out.println(" Sum " sum)
• count0 sum 0
• count 3 sum 033
• count 6 sum 369
• count 9 sum 9918

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Homework 1

• 27. int nextToPrint 1
• int maximum 10
• while(nextToPrint lt maximum)
• if (nextToPrint 2 ! 0)
• System.out.print(nextToPrint" ")
• nextToPrint nextToPrint 1
• System.out.println()
• 1 3 5 7 9

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Homework 1

• 28. int sum0
• int i0
• while (ilt5)
• int j4
• while (i!j)
• sum j
• jj-1
• i
• System.out.println(" Sum "sum)

Sum 30
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Homework 1

• sum0 i0
• j4
• sum 04 4
• j3
• sum 43 7
• j2
• sum 72 9
• j1
• sum 9110

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Homework 1

• i1
• j4
• sum 104 14
• j3
• sum 143 17
• j2
• sum 172 19

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Homework 1

• i2
• j4
• sum 194 23
• j3
• sum 233 26

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Homework 1

• i3
• j4
• sum 264 30