Untitled Quiz

Data Structures and Algorithms - ECE251 Tutorial 5

• Object-Oriented Programming (OOP) was presented in this tutorial.
• Classes and Objects: A class acts as a blueprint for objects. Objects are instances of a class, like houses built from a blueprint.
• Object-Oriented Programming Terminology:
  • Attributes: Members of a class.
  • Methods or Behaviors: Member functions of a class.
• Access Specifiers: Control access to class members.
  • Public: Accessible from outside the class.
  • Private: Can only be accessed by members of the class.
  • Protected: Accessible by members of the class and derived classes.
• Class Example (Rectangle):
  • Private members (width, length) are internal to the class.
  • Public members (setWidth, setLength, getWidth, getLength, getArea) are accessible from outside.
• Defining an Instance of a Class: A class instance is an object.
  • Allocate via structure variables (e.g., Rectangle r;).
  • Functions are accessed using dot operator (e.g., r.setWidth(5.2);).
  • Accessing private members through the dot operator results in a compiler error.
• Defining Member Functions:
  • Member function protoype is declared within the class.
  • Functions are defined outside the class using the scope resolution operator (::).
• Using const with Member Functions: The const keyword, used with member functions, indicates that the function will not modify the object's data.
• Example program (Program 13-1):
  • Demonstrates a Rectangle class.
  • Shows getting user input for rectangle dimensions.
  • Calculates and displays the rectangle's area.
• Avoiding Stale Data: It's crucial to calculate derived data (like area) within methods rather than storing it in a variable to avoid stale (incorrect) data if other aspects of the object change.
• Constructors: A special method automatically called when creating an object.
  • Constructor name is the class name.
  • Has no return type.
  • If no custom constructor is specified, a default constructor is automatically provided by the compiler.
  • Demonstrated with example code.
• Passing Arguments to Constructors:
  • Takes parameters in the prototype.
  • Arguments are passed to the constructor when the object is created.
• Overloading Constructors: A class can have multiple constructors with different parameter lists.
• Dynamically Allocating an Object:
  • Allocating objects using new dynamically in memory.
  • Importance of delete to free memory.
• Destructors: A special method automatically called when the object is destroyed.
  • Has no return type.
  • Release dynamically created memory.
• Arrays of Objects: Creating arrays of objects.
  • Initializing using a constructor with arguments.
• Accessing Objects in Arrays:
  • Using subscripts for object access.
  • Call methods using dot notation.

Inheritance

• Inheritance: A class inherits properties and methods from another class, similar to a child inheriting traits from a parent.

Encapsulation

• Encapsulation: The mechanism to hide internal object state.
• Public methods are used to interact with the object.
• Examples of object interaction using the setData (setter) and getData (getter) methods.

Abstraction

• Abstraction: Hiding the complex implementation details while providing a simplified interface.
• A real-world example is a TV remote that allows interactions with a TV without showing how it works internally.

Polymorphism

• Polymorphism: The ability of an object to take on many forms.
• Methods with the same name can behave differently depending on the object.
• Illustrated with example code demonstrating the sound() method in different animal classes.

Question

• Problem Statement: Develop a program in OOP to track employee names, birth years, and years of experience and determine their age.

• Solution:

  • Create an Employee class with attributes for name, birth year, and experience.
  • A constructor initialized these attributes.
  • Class method to calculate the age using the birth year.
  • Display the details in a main method.