Questions and Answers
Which of the following is the most appropriate implementation of the Cat class?
Which of the following is the most appropriate implementation of the Party class?
Which statement will create a Cat object that represents a cat that is considered a senior cat?
Cat c = new Cat("Whiskers", 10);
What is a missing constructor code to create a Cat object with attributes set to "black" and true?
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What are reasonable preconditions for the TestScore constructor?
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What is the most appropriate precondition for the method 'getiToEnd' so that it does not throw an exception?
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Which of the following is the most appropriate implementation of the Cat class?
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Which statement will create a Party object that has three people?
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What constructor can replace missing code to correctly create a Party object with numOfPeople and volumeOfMusic?
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What is the correct constructor for the Liquid class?
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Study Notes
Cat Class Implementation
- The Cat class has two attributes:
name
(String) andage
(int). - A constructor initializes these attributes:
public Cat(String name, int age)
.
Party Class Implementation
- The Party class features three attributes:
numOfPeople
,volumeOfMusic
, andnumOfBoxesOfPizza
(all int). - It includes a constructor and a method
startParty()
accessible outside the class:public Party() { }
andpublic void startParty() { }
.
Senior Cat Determination
- The Cat class can determine if a cat is a senior based on age.
- A cat is classified as senior if its age is 10 or higher:
if (age >= 10) { isSenior = true; }
. - Example of senior cat creation:
Cat c = new Cat("Whiskers", 10);
.
Cat Creation Variants
- Two valid ways to initiate a Cat object that is 5 years old with no kittens:
-
Cat c = new Cat("Sprinkles", 5, 0);
-
Cat c = new Cat("Luna", 5);
-
- Attempting to create a cat with a negative age or incorrect parameter combinations is invalid.
Constructing Cat with Attributes
- The Cat class can be initialized with specific attributes like color and hunger status.
- Example constructor to create a black, hungry cat:
public Cat(String c, boolean h) { color = c; isHungry = h; }
. - Object creation example:
Cat c = new Cat("black", true);
.
TestScore Class
- The TestScore class has attributes:
studentName
(String),score
(double), andextraCredit
(double). - Reasonable preconditions require valid data inputs for the constructor.
Method Preconditions
- For the method
getiToEnd(String str, int i)
, ensure thati
is within bounds to prevent exceptions. - Appropriate example of initializing class attributes through a constructor.
Liquid Class Implementation
- The Liquid class includes attributes for boiling point and freezing point.
- Constructor:
public Liquid(double boilingPoint, double freezingPoint) {}
initializes these values.
Party Object Creation
- A Party can be constructed with the host's name and number of attendees.
- Example of creating a party object with three attendees:
Party p = new Party("Eduardo", 3);
.
Multiple Constructors in Party Class
- The Party class can be designed with multiple constructors to handle different inputs.
- Example constructor allows initializing with host name, number of people, and capacity:
-
Party(String name, int num, int cap)
and -
Party(String name, int cap)
which defaultsnumOfPeople
to zero.
-
Validating Party Attributes
- Party creation statements:
-
Party b = new Party("Charlie", 78);
-
Party b = new Party("Charlie", 0, 78);
- All provided statements are valid, accommodating various initialization needs.
-
Object Initialization Syntax
- The Party class constructor that takes parameters can be structured clearly to set attributes simultaneously.
- Ensure that class objects such as Party or Liquid are initialized properly with appropriate constructors.
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Description
This quiz consists of flashcards focused on key concepts in Computer Science, particularly object-oriented programming. You will explore class implementations and constructors in Java with practical examples. Test your knowledge and understanding of various structures used in programming.