CSE205 Lecture 06

Object-Oriented Programming and Data Structures
Inheritance I
(202202)

Transcript

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   CSE 205
   Object-Oriented Programming and
   Data Structures
   Lecture 06: Inheritance I
   Dr. Javier Gonzalez-Sanchez
   javiergs@asu.edu
   javiergs.engineering.asu.edu | javiergs.com
   PERALTA 230U
   Office Hours: By appointment
   

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   Inheritance
   

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3. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 3
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   Inheritance
   § Instead of repeating similar data/method definitions in several classes, we
   can define one class with the common instance data/methods, and let other
   classes inherit (extend) these data/method definitions.
   § Java: parent (super) class and child (sub) class
   § C++: base class and derived class
   § New class inherits existing members (variables and functions),
   add members, and
   redefine members
   

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4. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 4
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   Single Inheritance
   § Java supports single inheritance only, i.e.,
   A child class can have only one parent class
   (direct parent, not ancestors)
   

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5. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 5
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   Classes
   

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6. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 6
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   Classes are Better with a Family
   

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7. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 7
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   Classes are Better with a Family
   

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8. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 8
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   Classes are Better with a Family
   

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9. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 9
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   Protected
   § Child classes do not inherit private variables
   § Protected variables and methods can be inherited by child classes, but not
   as accessible as public
   § If you plan to have a class inherited by other classes, its data should be
   declared as protected
   

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10. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 10
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    Protected
    

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11. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 11
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    Classes are Better with a Family
    

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12. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 12
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    Classes are Better with a Family (UML)
    

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13. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 13
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    Note
    In the Class Diagram:
    § Parameters are optional
    § Inherited members are implicit, just like with the source code
    

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    Inheritance
    Constructors
    

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15. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 15
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    Inheritance
    § Constructors are not inherited
    § A child’s constructor is responsible for calling its parent’s constructor.
    § Keyword: super
    

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16. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 16
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    Person
    

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17. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 17
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    Student and Professor
    

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18. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 18
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    Main
    What is the output?
    

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19. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 19
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    Main
    

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    To be Continued…
    

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21. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 21
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    Questions
    

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    CSE 205 Object-Oriented Programming and Data Structures
    Javier Gonzalez-Sanchez, Ph.D.
    javiergs@asu.edu
    Spring 2022
    Copyright. These slides can only be used as study material for the class CSE205 at Arizona State University.
    They cannot be distributed or used for another purpose.
    

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