CS110 Lecture 10 Mar 9, 2005

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CS110- Lecture 10Mar 9, 2005

• Agenda
• Practice Session (classes and loops)
• JUnit Testing
• Practice Session (testing)

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Practice Session (Extra Credit)

• Design and implement a class called Circle that
  contains instance data that represents the
  circles radius. Define the Circle constructor to
  accept and initialize the radius, and include
  getter and setter methods for the radius. Include
  method area that calculates and return the area
  and another method perimeter that calculates and
  return the perimeter.

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Practice Session (Extra Credit)

• Design and implement a class called Person that
  contains instance data that represents the
  persons name and age. Define the Person
  constructor to accept and initialize the name and
  age, and include getter and setter methods for
  the name and age.
• Create a driver class called PersonClient whose
  main method instantiates and update several
  Person objects.

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Practice Session (Extra Credit)

• Design and implement a class called Book that
  contains instance data that represents the books
  title, author, publisher, edition and isbn
  number. Define the Book constructor to accept and
  initialize the instance data, and include getter
  and setter methods for all instance data.
• Create a driver class called BookShelf whose main
  method instantiates and update several Book
  objects.

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Practice Session (Page 277)

• 5.17 Write a for loop to print the odd numbers
  from 1 to 99.
• 5.18 Write a for loop to print the multiples of
  3 from 300 down to 3.
• 5.19 Write a code fragment that reads 10 integer
  values from the user and prints the highest value
  entered.
• 5.20 Write a code fragment that determines and
  prints the number of times the character a
  appears in a String object called name.
• 5.21 Write a code fragment that prints the
  characters stored in a String object called str
  backward.

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Practice Session (Page 277)

• 5.22 Write a code fragment that prints every
  other character in a String object called word
  starting from the first character.
• 5.23 Write a method called powersOfTwo that
  prints the first 10 powers of 2 (starting with
  2). The method takes no parameter and doesnt
  return anything.

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Practice Session
Class Name
Point
x double y double
Data
getX() double getY() double setX (double x1)
void setY (double y1) void
Methods
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Testing

• Unit Testing To test each unit, or component,
  independently, before the units are integrated
  into the whole system.
• Integration and system testing To integrate all
  the components of a system and to test the system
  as a whole.

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Unit Testing

• Unit testing is important because
• For the whole system to function properly, each
  of its components, or units, must function
  properly individually.
• Units are much smaller than the whole system, it
  is much easier to find the errors in each unit
  individually.
• Good unit testing will reduce the effort and cost
  required for integration significantly.

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Unit Testing

• In OOP the unit for unit testing is often a
  single class.
• Old style of testing Carry out tests in main
  method.
• New style of testing Write separate test classes
  for testing purposes only.

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JUnit Testing

• When dealing with large set of test cases it is
  usually more convenient to use a unit testing
  tool.
• JUnit is a flexible, easy to use, and open source
  unit testing tool for java programs.

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Template of a typical JUnit test program
public class TestX extends TestCase // X is the
class // to be tested private X x
null protected void setUp() throws Exception
x new X() protected void
tearDown() throws Exception x null
//All test methods are public/protected not
private public void testCase1()
//test and compare results public void
testCase2() //test and compare results

setUp is called before every testCase is executed
tearDown is called after every testCase is
executed
Name of test methods starts with test
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Test class for Die.java
public class TestDie extends TestCase //Die is
the class //to be tested private
Die die null protected void setUp() throws
Exception die new Die() protected
void tearDown() throws Exception die
null public void testGetFaceValue()
//test and compare results int
expectedReturn 1 int actualReturn
die.getFaceValue() assertEquals(expectedRetu
rn,actualReturn)
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JUnit features

• JUnit features include
• Assertions for testing expected results
• Test fixtures (setUp and tearDown) for sharing
  common test data.
• Graphical and textual test runners