Recitation

1
Recitation
Qi ZhangOct 22
COMP 110 Introduction to Programming
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Todays Lecture

• Solution to Assignment 3
• A brief review of the mid-term

2
3
Assign.3

• Class Name Statistics
• fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

• UML

3
4
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
UNCStats

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

5
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
UNCStats

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

6
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

7
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
692
UNCStats

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

8
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats
692
145

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• Int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

9
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats
692
145

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

398
10
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats
692
145

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

398
11
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats
692
145

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

398
12
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats
692
145

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

398
13
Assign.3

• Class Name Statistics
• - fieldGoalsMade (int)
• fieldGoalAttempts (int)
• freeThrowsMade (int)
• freeThrowAttempts (int)
• - threePintersMade (int)
• - threePointAttempts (int)
• setFieldGoalsMade(int fieldMade)void
• setFieldGoalAttempts(int fieldAttempts)void
• setFreeThrowsMade(int freeMade)void
• setFreeThrowAttempts(int freeAttempts)void
• set3PointersMade(int threeMade)void
• set3PointersAttempt(int threeAttempts)void
• getTotalPoints() int
• getFieldGoalPercent() double
• getFreeThrowPercent() double

841
1753
524
UNCStats
692
145

• unc.setFieldGoalsMade(841)
• unc.setFieldGoalAttempts(1753)
• unc.setFreeThrowsMade(524)
• unc.setFreeThrowAttempts(692)
• unc.set3PointersMade(145)
• unc.set3PointAttempts(398)
• int points unc.getTotalPoints()
• double field unc.getFieldGoalPercent()
• double free unc.getFreeThrowPercent()
• double three unc.get3PointPercent()

398
14
Defining Data Members

• private int fieldGoalsMade
• private int fieldGoalAttempts
• private int freeThrowsMade
• private int freeThrowAttempts
• private int threePintersMade
• private int threePointAttempts

Access modifier
14
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Defining Data Members

• private int fieldGoalsMade
• private int fieldGoalAttempts
• private int freeThrowsMade
• private int freeThrowAttempts
• private int threePintersMade
• private int threePointAttempts

Access modifier
type
15
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Defining Data Members

• private int fieldGoalsMade
• private int fieldGoalAttempts
• private int freeThrowsMade
• private int freeThrowAttempts
• private int threePintersMade
• private int threePointAttempts

Access modifier
variable names
type
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Defining Data Members

• private int fieldGoalsMade
• private int fieldGoalAttempts
• private int freeThrowsMade
• private int freeThrowAttempts
• private int threePintersMade
• private int threePointAttempts

not double !!!!!
Do typecasting later!! double fieldGoalPercent
(double) fieldGoalsMade / (double)
fieldGoalsAttempts
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Private or Public Instance Variables?

• Public any other class or program can directly
  access and change the instance variables
• unc.fieldGoalsMade
  1000000
• Private the instance varaibles name is not
  accessible outside of the class definition.
• unc.fieldGoalsMade 1000000
  illegal
• Normally, we define the instance variables as
  private
• force the programmer who uses the class to access
  the instance variables only via methods.
• Define accessor methods and mutator methods for
  accessing the private variables
• unc.setFieldGoalsMade(1000000)

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Other variables?

• int totalPoints
• double fieldGoalPercent
• double freeGoalPercent
• double threePointerPercent
• We do not need to define them as instance
  variables
• They should be defined as local variables in
  the methods where we compute them

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Mutator Methods

• public void setFieldGoalsMade(int fieldMade)
• public void setFieldGoalAttempts(int
  fieldAttempts)
• public void setFreeThrowsMade(int freeMade)
• public void setFreeThrowAttempts(int
  freeAttempts)
• public void set3PointersMade(int threeMade)
• public void set3PointersAttempt(int
  threeAttempts)

Public! Void! Requires parameter!
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Mutator Methods
841

• public void setFieldGoalsMade(int fieldMade)
• fieldGoalsMade fieldMade

parameter
Instance variable
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Mutator Methods

• public void setFieldGoalsMade(int fieldGoalsMade)
• this.fieldGoalsMade fieldGoalsMade

parameter
Instance variable
Current object
Parameter and instance variable are having the
same name
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Accessor Methods

• Public int getTotalPoints()
• public double getFieldGoalPercent()
• public double getFreeThrowPercent()
• public double get3PointPercent()

Public! Has return value! Never void! Does not
require parameter!
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Accessor Methods

• public double getFieldGoalPercent()
  return ((double)fieldGoalsMade/(double)fieldGoalAt
  tempts)100

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Accessor Methods

• public double getFieldGoalPercent()
  return ((double)fieldGoalsMade/(double)fieldGoalAt
  tempts)100

Instance variable (int)
typecasting
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Accessor Methods

• public double getFieldGoalPercent()
  return ((double)fieldGoalsMade/(double)fieldGoalAt
  tempts)100
• Define local variable fieldGoalsPercent
• public double getFieldGoalPercent()
  double fieldGoalsPercent
• (double)fieldGoalsMade/
  (double)fieldGoalAttempts
• return fieldGoalsPercent100

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Some other problems

• Meaningful names!!
• fieldGoalsMade Good
• fgm Bad
• Do not need to import any packages
• Better to define each instance variable in a
  separate line
• getMisses() ???

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