The document discusses object-oriented programming concepts like classes, objects, methods, and constructors in Java. It explains that a class defines the template for objects, with members like variables and methods. An object is an instance of a class that occupies space in memory. Methods define the interface to classes. Constructors initialize objects upon creation and can set initial variable values. The document provides examples of defining Box classes with variables, methods to return volume, and constructors to initialize dimensions.
The document discusses object-oriented programming concepts like classes, objects, methods, properties, encapsulation, inheritance, and polymorphism. It provides examples of defining classes in Java with properties, methods, and constructors. A class acts as a blueprint that defines the data and behavior of objects. Objects are instances of a class that can access class methods and properties. The document also covers access modifiers and how they control access to class elements.
The document discusses various concepts related to C++ classes including:
1. Structure definitions, accessing structure members using dot operator and pointers. Class definitions include data members and member functions.
2. Class objects are created using the class name followed by the object name. Class members are accessed using dot operator. Member functions can be defined inside or outside the class.
3. Access specifiers like private, public, and protected control access to class members. Constructors and destructors are special member functions for object initialization and destruction.
Local variables are stored in memory during the execution of a function. When the function exits, the memory for local variables is deallocated. Local variables provide convenient temporary storage but have a short lifetime and cannot persist beyond the function call. Returning a pointer to a local variable from a function results in a dangling pointer as the memory is deallocated when the function exits.
This document discusses object-oriented programming concepts like abstraction, modularization, and how objects interact by calling each other's methods. It uses a digital clock example to demonstrate how an application can be divided into well-defined classes like NumberDisplay and ClockDisplay that cooperate by creating objects of each other's types and calling methods on those objects. The document also covers topics like class diagrams, object diagrams, primitive vs. object types, object creation, method overloading, and distinguishing internal from external method calls.
This document discusses how to implement various UML diagrams in code, including class diagrams, state diagrams, activity diagrams, sequence diagrams, and collaboration diagrams. It provides examples of implementing classes, inheritance, associations, aggregation, composition, and persistence. Key implementation strategies covered include using vectors and hashtables to represent associations, creating separate association classes, and mapping classes to database tables.
The document discusses object-oriented programming concepts in C#, including classes, constructors, destructors, and access modifiers. It provides examples of how to define classes with properties, methods, and constructors. It also explains the differences between public, private, and protected access modifiers and how they control accessibility of class members both within and outside of a class. The document contains code examples demonstrating the usage of classes, constructors, and access modifiers in C#.
Here is the Cuboid class with private instance variables, public volume() method, setter and getter methods as specified in the question:
public class Cuboid {
private double length;
private double breadth;
private double height;
public double volume() {
return length * breadth * height;
}
public boolean setLength(double len) {
if(len > 0) {
this.length = len;
return true;
}
return false;
}
public boolean setBreadth(double bre) {
if(bre > 0) {
this.breadth = bre;
return true;
}
return false;
}
public boolean setHeight(double hei
1. The document discusses a lecture on object oriented programming in C++. It introduces classes and objects, and explains how to declare a class and create objects in C++.
2. It provides an example class called CRectangle with data members and member functions to demonstrate class structure and how to define functions inside and outside the class.
3. The lecture concludes with providing some examples programs to demonstrate class concepts and exercises for students to practice.
The document discusses object-oriented programming concepts like classes, objects, methods, properties, encapsulation, inheritance, and polymorphism. It provides examples of defining classes in Java with properties, methods, and constructors. A class acts as a blueprint that defines the data and behavior of objects. Objects are instances of a class that can access class methods and properties. The document also covers access modifiers and how they control access to class elements.
The document discusses various concepts related to C++ classes including:
1. Structure definitions, accessing structure members using dot operator and pointers. Class definitions include data members and member functions.
2. Class objects are created using the class name followed by the object name. Class members are accessed using dot operator. Member functions can be defined inside or outside the class.
3. Access specifiers like private, public, and protected control access to class members. Constructors and destructors are special member functions for object initialization and destruction.
Local variables are stored in memory during the execution of a function. When the function exits, the memory for local variables is deallocated. Local variables provide convenient temporary storage but have a short lifetime and cannot persist beyond the function call. Returning a pointer to a local variable from a function results in a dangling pointer as the memory is deallocated when the function exits.
This document discusses object-oriented programming concepts like abstraction, modularization, and how objects interact by calling each other's methods. It uses a digital clock example to demonstrate how an application can be divided into well-defined classes like NumberDisplay and ClockDisplay that cooperate by creating objects of each other's types and calling methods on those objects. The document also covers topics like class diagrams, object diagrams, primitive vs. object types, object creation, method overloading, and distinguishing internal from external method calls.
This document discusses how to implement various UML diagrams in code, including class diagrams, state diagrams, activity diagrams, sequence diagrams, and collaboration diagrams. It provides examples of implementing classes, inheritance, associations, aggregation, composition, and persistence. Key implementation strategies covered include using vectors and hashtables to represent associations, creating separate association classes, and mapping classes to database tables.
The document discusses object-oriented programming concepts in C#, including classes, constructors, destructors, and access modifiers. It provides examples of how to define classes with properties, methods, and constructors. It also explains the differences between public, private, and protected access modifiers and how they control accessibility of class members both within and outside of a class. The document contains code examples demonstrating the usage of classes, constructors, and access modifiers in C#.
Here is the Cuboid class with private instance variables, public volume() method, setter and getter methods as specified in the question:
public class Cuboid {
private double length;
private double breadth;
private double height;
public double volume() {
return length * breadth * height;
}
public boolean setLength(double len) {
if(len > 0) {
this.length = len;
return true;
}
return false;
}
public boolean setBreadth(double bre) {
if(bre > 0) {
this.breadth = bre;
return true;
}
return false;
}
public boolean setHeight(double hei
1. The document discusses a lecture on object oriented programming in C++. It introduces classes and objects, and explains how to declare a class and create objects in C++.
2. It provides an example class called CRectangle with data members and member functions to demonstrate class structure and how to define functions inside and outside the class.
3. The lecture concludes with providing some examples programs to demonstrate class concepts and exercises for students to practice.
This document provides an overview of object-oriented programming concepts in Visual Basic, including classes, objects, fields, properties, methods, constructors, destructors, inheritance, polymorphism, and interfaces. It discusses key Visual Basic concepts like classes, objects, access specifiers, and shows examples of creating a class with fields and properties. It also covers more advanced topics such as inheritance, polymorphism, abstract classes, interfaces, and collections.
This document discusses building graphical user interfaces in Java. It covers GUI principles like components, layout, and event handling. It also describes common Swing and AWT components like frames, menus, buttons and how to arrange them. The document uses an image viewer application as an example to demonstrate creating GUIs, loading images, handling events, filters and other GUI features.
This document provides an overview and outline of a lesson on variables and types in Java. The key points covered include:
- Variables are names for locations in memory that hold values. Primitive data types include numerical, character, and boolean values. Complex objects are instances of classes.
- Variables are declared with a data type, name, and optional initial value. Primitive values can be output and converted between types through casting or automatic promotion.
- Expressions combine operators and operands to compute results. Operators have precedence that determines the order of evaluation. Assignment operators store the result of an expression into a variable.
- The lesson covers primitive data types, variables, expressions, output, conversion, and creating objects
Polymorphism allows methods to be used generically for a wide range of object arguments, known as generic programming. When a method takes a superclass as a parameter, any subclass of that parameter can be passed to the method. At runtime, the specific implementation of the method invoked is determined dynamically based on the actual object passed. This capability is known as dynamic binding. Casting may be needed when assigning an object to a variable of a superclass or subclass in the inheritance hierarchy.
This chapter discusses user-defined classes and abstract data types (ADTs) in Java. It covers defining classes with private, protected, public, and static members. Constructors and finalizers are examined. The toString method is explored. Abstract data types are introduced as data types that specify logical properties without implementation details. An example candy machine problem is presented to demonstrate defining classes for a non-GUI and GUI application to model a candy machine with items for sale, a cash register, dispenser, and other components.
The document discusses advanced functionality in Java using library classes. It covers using library classes like Set and Map to implement tokenized strings and phone book functionality. It also discusses writing documentation for classes using javadoc comments for classes, constructors and methods. The documentation should describe the purpose, parameters and return values of methods to allow other programmers to use the class without seeing the implementation code.
AN EMPIRICAL COMPARISON OF WEIGHTING FUNCTIONS FOR MULTI-LABEL DISTANCEWEIGHT...cscpconf
Multi-label classification is an extension of classical multi-class one, where any instance can be
associated with several classes simultaneously and thus the classes are no longer mutually
exclusive. It was experimentally shown that the distance-weighted k-nearest neighbour
(DWkNN) algorithm is superior to the original kNN rule for multi-class learning. But, it has not
been investigated whether the distance-weighted strategy is valid for multi-label learning and
which weighting function performs well. In this paper, we provide a concise multi-label DWkNN form (MLC-DWkNN). Furthermore, four weighting functions, Dudani’s linear function varying from 1 to 0, Macleod’s linear function ranging from 1 to 1/2, Dudani’s inverse distance function, and Zavrel’s exponential function, are collected and then investigated by detailed experiments on three benchmark data sets with Manhattan distance. Our study demonstrates that Dudani’s linear and Zavrel’s exponential functions work well, and moreover MLC-DWkNN with such two functions outperforms an existing kNN-based multi-label classifier ML-kNN
Object Oriented Programming Concepts using JavaGlenn Guden
This document discusses object-oriented programming and compares old procedural programming techniques using structures to the newer object-oriented approach using classes. Specifically:
- Old programming used structures to define data types and separate functions to operate on those structures.
- The new object-oriented approach defines classes that encapsulate both the data structure and functions together as objects.
- Some key benefits of the object-oriented approach are that new types of objects can be added without changing existing code, and that new objects can inherit features from existing objects, making the code easier to modify.
C# (This keyword, Properties, Inheritance, Base Keyword)Umar Farooq
The document discusses key object-oriented programming concepts in C#, including inheritance, encapsulation, and the use of the 'this' and 'base' keywords. Specifically:
1. It explains how the 'this' keyword is used to refer to properties and methods of the current class instance. It provides an example demonstrating accessing class variables vs local variables.
2. It describes properties in C# and how they are used to encapsulate data through getters and setters. Examples are given for read-write and read-only properties.
3. Inheritance is introduced as a fundamental OOP principle. The document defines inheritance and provides a code example demonstrating a base Shape class and derived Triangle class.
4Developers 2018: Ile (nie) wiesz o strukturach w .NET (Łukasz Pyrzyk)PROIDEA
Kiedy ostatnio stworzyłeś nową strukturę pisząc aplikację w .NET? Wiesz do czego wykorzystywać struktury i jak mogą one zwiększyć wydajność Twojego programu? W prezentacji pokażę czym charakteryzują się struktury, jak dużo różni je od klas oraz opowiem o kilku ciekawych eksperymentach.
The document discusses access modifiers in Java and their usage with variables, functions, and classes at different levels. It explains that access modifiers like private, protected, default, and public determine whether elements are visible from within the same class, package, subclass, or any class. Private is most restrictive while public is most accessible. It also covers other concepts like static methods, inheritance, polymorphism, abstract classes, interfaces and exception handling in Java.
Class notes(week 6) on inheritance and multiple inheritanceKuntal Bhowmick
java notes, object oriented programming using java, java tutorial, lecture notes, java programming notes, java example programs, java programs with explanation, java source code with output, java programs, java coding, java codes, java slides, java notes,inheritance in java, java inheritancenotes, java inheritancet notes,different types of inheritance in Java,inheritance with an example, inheritance hierarchy in Java
The document discusses object-oriented programming concepts in Java, including:
1) Similarities and differences between Java and C++, such as single inheritance in Java.
2) Core object-oriented terminology like "class" and "object".
3) Examples demonstrating instance variables, methods, and constructors in Java classes. The examples show how to define classes, create objects, access fields and call methods.
Cluster analysis involves grouping data objects into clusters so that objects within the same cluster are more similar to each other than objects in other clusters. There are several major clustering approaches including partitioning methods that iteratively construct partitions, hierarchical methods that create hierarchical decompositions, density-based methods based on connectivity and density, grid-based methods using a multi-level granularity structure, and model-based methods that find the best fit of a model to the clusters. Partitioning methods like k-means and k-medoids aim to optimize a partitioning criterion by iteratively updating cluster centroids or medoids.
The document discusses object-oriented programming concepts like inheritance, subclasses, and superclasses. It provides examples of inheritance hierarchies for different classes like Shapes, CommunityMembers, and BankAccounts. The key points are:
- Inheritance allows subclasses to inherit and customize behaviors from superclasses for code reusability.
- Subclasses are more specialized groups of objects that inherit data and behaviors from their superclasses.
- Java supports single inheritance but not multiple inheritance.
- Relationships between superclasses and subclasses form a hierarchical tree structure.
- Access modifiers like private and protected determine whether subclass instances can access members of superclasses.
The document discusses finding initial parameters for neural networks used in data clustering. It presents a modified K-means fast learning artificial neural network (K-FLANN) algorithm that uses differential evolution to optimize the vigilance and tolerance parameters of K-FLANN. Differential evolution is used to select parameter values that yield good clustering performance. The modified K-FLANN algorithm is evaluated on several data sets and shown to provide promising results in terms of convergence rate and accuracy compared to other algorithms. Comparisons are also made between the original and modified versions of K-FLANN.
Classes and objects allow bundling of related data and functions. An object is an instance of a class that contains the class's data members and can access its member functions. Classes improve on procedural programming by avoiding issues when data structures change. A class defines the data types and functions for a user-defined type using a class name, data members, and member functions. Objects are instances of classes that hold separate copies of class data. Access specifiers like public, private, and protected control access to class members.
This document discusses using collections and iterators in Java. It covers using the ArrayList class from the java.util package to store an arbitrary number of objects. It describes adding, removing, and retrieving objects from the collection. It also discusses using while loops and iterators to iterate through collections, and using arrays for fixed-size collections. The for loop is presented as an alternative to the while loop for known repetition needs like iterating over arrays.
The document discusses structures and classes in C++. It defines a structure called student with data members like name and roll number. It then defines a class called person with data members name and number and demonstrates creating an object of the class and accessing its members. The document also discusses concepts like defining member functions inside and outside classes, access specifiers, nesting member functions, and making outside member functions inline.
This document discusses classes and objects in Java. Some key points:
- A class defines a new data type that can be used to create objects. An object is an instance of a class.
- A class contains variables (instance variables) and methods as members. Variables store data for each object, while methods define behaviors.
- Objects are created using the new operator and assigned to a reference variable of the class type. Multiple references can refer to the same object.
- Methods can access and modify the instance variables of the object they are called on using the this keyword. Constructors initialize new objects and can take parameters.
This document discusses object-oriented programming concepts in Java including:
- Classes define templates for objects with similar attributes and behaviors.
- Objects are instances of classes that represent real-world entities. They have attributes like properties and behaviors like methods.
- Methods operate on instances of classes. Constructors initialize objects upon creation.
- Overloading allows multiple methods or constructors with the same name but different parameters.
- Objects can be passed as parameters and returned from methods. Arrays can hold multiple object references.
This document provides an overview of object-oriented programming concepts in Visual Basic, including classes, objects, fields, properties, methods, constructors, destructors, inheritance, polymorphism, and interfaces. It discusses key Visual Basic concepts like classes, objects, access specifiers, and shows examples of creating a class with fields and properties. It also covers more advanced topics such as inheritance, polymorphism, abstract classes, interfaces, and collections.
This document discusses building graphical user interfaces in Java. It covers GUI principles like components, layout, and event handling. It also describes common Swing and AWT components like frames, menus, buttons and how to arrange them. The document uses an image viewer application as an example to demonstrate creating GUIs, loading images, handling events, filters and other GUI features.
This document provides an overview and outline of a lesson on variables and types in Java. The key points covered include:
- Variables are names for locations in memory that hold values. Primitive data types include numerical, character, and boolean values. Complex objects are instances of classes.
- Variables are declared with a data type, name, and optional initial value. Primitive values can be output and converted between types through casting or automatic promotion.
- Expressions combine operators and operands to compute results. Operators have precedence that determines the order of evaluation. Assignment operators store the result of an expression into a variable.
- The lesson covers primitive data types, variables, expressions, output, conversion, and creating objects
Polymorphism allows methods to be used generically for a wide range of object arguments, known as generic programming. When a method takes a superclass as a parameter, any subclass of that parameter can be passed to the method. At runtime, the specific implementation of the method invoked is determined dynamically based on the actual object passed. This capability is known as dynamic binding. Casting may be needed when assigning an object to a variable of a superclass or subclass in the inheritance hierarchy.
This chapter discusses user-defined classes and abstract data types (ADTs) in Java. It covers defining classes with private, protected, public, and static members. Constructors and finalizers are examined. The toString method is explored. Abstract data types are introduced as data types that specify logical properties without implementation details. An example candy machine problem is presented to demonstrate defining classes for a non-GUI and GUI application to model a candy machine with items for sale, a cash register, dispenser, and other components.
The document discusses advanced functionality in Java using library classes. It covers using library classes like Set and Map to implement tokenized strings and phone book functionality. It also discusses writing documentation for classes using javadoc comments for classes, constructors and methods. The documentation should describe the purpose, parameters and return values of methods to allow other programmers to use the class without seeing the implementation code.
AN EMPIRICAL COMPARISON OF WEIGHTING FUNCTIONS FOR MULTI-LABEL DISTANCEWEIGHT...cscpconf
Multi-label classification is an extension of classical multi-class one, where any instance can be
associated with several classes simultaneously and thus the classes are no longer mutually
exclusive. It was experimentally shown that the distance-weighted k-nearest neighbour
(DWkNN) algorithm is superior to the original kNN rule for multi-class learning. But, it has not
been investigated whether the distance-weighted strategy is valid for multi-label learning and
which weighting function performs well. In this paper, we provide a concise multi-label DWkNN form (MLC-DWkNN). Furthermore, four weighting functions, Dudani’s linear function varying from 1 to 0, Macleod’s linear function ranging from 1 to 1/2, Dudani’s inverse distance function, and Zavrel’s exponential function, are collected and then investigated by detailed experiments on three benchmark data sets with Manhattan distance. Our study demonstrates that Dudani’s linear and Zavrel’s exponential functions work well, and moreover MLC-DWkNN with such two functions outperforms an existing kNN-based multi-label classifier ML-kNN
Object Oriented Programming Concepts using JavaGlenn Guden
This document discusses object-oriented programming and compares old procedural programming techniques using structures to the newer object-oriented approach using classes. Specifically:
- Old programming used structures to define data types and separate functions to operate on those structures.
- The new object-oriented approach defines classes that encapsulate both the data structure and functions together as objects.
- Some key benefits of the object-oriented approach are that new types of objects can be added without changing existing code, and that new objects can inherit features from existing objects, making the code easier to modify.
C# (This keyword, Properties, Inheritance, Base Keyword)Umar Farooq
The document discusses key object-oriented programming concepts in C#, including inheritance, encapsulation, and the use of the 'this' and 'base' keywords. Specifically:
1. It explains how the 'this' keyword is used to refer to properties and methods of the current class instance. It provides an example demonstrating accessing class variables vs local variables.
2. It describes properties in C# and how they are used to encapsulate data through getters and setters. Examples are given for read-write and read-only properties.
3. Inheritance is introduced as a fundamental OOP principle. The document defines inheritance and provides a code example demonstrating a base Shape class and derived Triangle class.
4Developers 2018: Ile (nie) wiesz o strukturach w .NET (Łukasz Pyrzyk)PROIDEA
Kiedy ostatnio stworzyłeś nową strukturę pisząc aplikację w .NET? Wiesz do czego wykorzystywać struktury i jak mogą one zwiększyć wydajność Twojego programu? W prezentacji pokażę czym charakteryzują się struktury, jak dużo różni je od klas oraz opowiem o kilku ciekawych eksperymentach.
The document discusses access modifiers in Java and their usage with variables, functions, and classes at different levels. It explains that access modifiers like private, protected, default, and public determine whether elements are visible from within the same class, package, subclass, or any class. Private is most restrictive while public is most accessible. It also covers other concepts like static methods, inheritance, polymorphism, abstract classes, interfaces and exception handling in Java.
Class notes(week 6) on inheritance and multiple inheritanceKuntal Bhowmick
java notes, object oriented programming using java, java tutorial, lecture notes, java programming notes, java example programs, java programs with explanation, java source code with output, java programs, java coding, java codes, java slides, java notes,inheritance in java, java inheritancenotes, java inheritancet notes,different types of inheritance in Java,inheritance with an example, inheritance hierarchy in Java
The document discusses object-oriented programming concepts in Java, including:
1) Similarities and differences between Java and C++, such as single inheritance in Java.
2) Core object-oriented terminology like "class" and "object".
3) Examples demonstrating instance variables, methods, and constructors in Java classes. The examples show how to define classes, create objects, access fields and call methods.
Cluster analysis involves grouping data objects into clusters so that objects within the same cluster are more similar to each other than objects in other clusters. There are several major clustering approaches including partitioning methods that iteratively construct partitions, hierarchical methods that create hierarchical decompositions, density-based methods based on connectivity and density, grid-based methods using a multi-level granularity structure, and model-based methods that find the best fit of a model to the clusters. Partitioning methods like k-means and k-medoids aim to optimize a partitioning criterion by iteratively updating cluster centroids or medoids.
The document discusses object-oriented programming concepts like inheritance, subclasses, and superclasses. It provides examples of inheritance hierarchies for different classes like Shapes, CommunityMembers, and BankAccounts. The key points are:
- Inheritance allows subclasses to inherit and customize behaviors from superclasses for code reusability.
- Subclasses are more specialized groups of objects that inherit data and behaviors from their superclasses.
- Java supports single inheritance but not multiple inheritance.
- Relationships between superclasses and subclasses form a hierarchical tree structure.
- Access modifiers like private and protected determine whether subclass instances can access members of superclasses.
The document discusses finding initial parameters for neural networks used in data clustering. It presents a modified K-means fast learning artificial neural network (K-FLANN) algorithm that uses differential evolution to optimize the vigilance and tolerance parameters of K-FLANN. Differential evolution is used to select parameter values that yield good clustering performance. The modified K-FLANN algorithm is evaluated on several data sets and shown to provide promising results in terms of convergence rate and accuracy compared to other algorithms. Comparisons are also made between the original and modified versions of K-FLANN.
Classes and objects allow bundling of related data and functions. An object is an instance of a class that contains the class's data members and can access its member functions. Classes improve on procedural programming by avoiding issues when data structures change. A class defines the data types and functions for a user-defined type using a class name, data members, and member functions. Objects are instances of classes that hold separate copies of class data. Access specifiers like public, private, and protected control access to class members.
This document discusses using collections and iterators in Java. It covers using the ArrayList class from the java.util package to store an arbitrary number of objects. It describes adding, removing, and retrieving objects from the collection. It also discusses using while loops and iterators to iterate through collections, and using arrays for fixed-size collections. The for loop is presented as an alternative to the while loop for known repetition needs like iterating over arrays.
The document discusses structures and classes in C++. It defines a structure called student with data members like name and roll number. It then defines a class called person with data members name and number and demonstrates creating an object of the class and accessing its members. The document also discusses concepts like defining member functions inside and outside classes, access specifiers, nesting member functions, and making outside member functions inline.
This document discusses classes and objects in Java. Some key points:
- A class defines a new data type that can be used to create objects. An object is an instance of a class.
- A class contains variables (instance variables) and methods as members. Variables store data for each object, while methods define behaviors.
- Objects are created using the new operator and assigned to a reference variable of the class type. Multiple references can refer to the same object.
- Methods can access and modify the instance variables of the object they are called on using the this keyword. Constructors initialize new objects and can take parameters.
This document discusses object-oriented programming concepts in Java including:
- Classes define templates for objects with similar attributes and behaviors.
- Objects are instances of classes that represent real-world entities. They have attributes like properties and behaviors like methods.
- Methods operate on instances of classes. Constructors initialize objects upon creation.
- Overloading allows multiple methods or constructors with the same name but different parameters.
- Objects can be passed as parameters and returned from methods. Arrays can hold multiple object references.
Class object method constructors in javaRaja Sekhar
Presented By :
N.V.Raja Sekhar Reddy
www.technolamp.co.in
www.programming9.com
Want more interesting...
Watch and Like us @ https://www.facebook.com/Technolamp.co.in
subscribe videos @ http://www.youtube.com/user/nvrajasekhar
The document discusses classes and methods in Java. It introduces the class as the fundamental building block of object-oriented programming in Java. A class defines the form and nature of an object by specifying its data and code. The document then discusses the general form of a class, including instance variables and methods. It provides examples of simple Box classes with instance variables like width, height, and depth. The document also discusses how to declare objects of a class and access instance variables using the dot operator. Finally, it introduces methods, how to add methods to a class, how methods can return values, and how methods can take parameters to make them more flexible and reusable.
Classes, Objects and Method - Object Oriented Programming with JavaRadhika Talaviya
The document discusses various object-oriented programming concepts in Java including classes, objects, constructors, method overloading, passing arguments, returning objects, recursion, the 'new' operator, 'this' and 'static' keywords, and inner classes. It provides examples to illustrate class and object declarations, creating objects using the new operator, using constructors, overloading methods and constructors, passing arguments by value and reference, returning objects from methods, using recursion to calculate factorials, and using the this and static keywords.
The document discusses the basics of classes and objects in Java. It defines a class as a template for creating objects that have both data fields (attributes) and methods. An object is an instance of a class that contains specific values for its attributes and can execute the methods defined in its class. The document provides examples of defining a Rectangle class with length and width attributes and methods to set their values and calculate the area. It also demonstrates how to declare objects of the Rectangle class and access their attributes and methods.
This document discusses key concepts in object-oriented programming with C++ including classes, objects, access modifiers, member functions, friend functions, and inline functions. It provides examples of how to define a class with data members and member functions, how to declare objects of a class, and how to define and call member functions and friend functions. It also demonstrates how to use access modifiers like public, private, and protected and how inline functions work.
This document provides an overview of classes, inheritance, and object-oriented programming concepts in Java. It discusses what classes are and how they are used to define new data types and create objects. It also covers class syntax, object creation, reference variables, constructors, methods, access control, static members, and other key concepts related to classes and objects in Java.
A class defines the blueprint for objects of a certain type. It contains variables to hold an object's state and methods to perform its behaviors. Constructors initialize new objects, while methods allow objects to interact. Objects are passed into methods by value for primitive types and by reference for class types. Classes use access modifiers like public and private to control variable and method visibility. Garbage collection automatically frees memory for unused objects. Method overloading and recursion allow methods to be reused in different contexts.
This document provides an introduction to creating and using classes in C#. Key points covered include defining classes with fields, methods, and constructors; using accessibility modifiers like public and private; calling methods and using the this keyword; creating static methods; and using listboxes, comboboxes, and events for selection changes. Examples are provided for defining classes, constructors, static and instance methods, and populating and accessing selection properties of list and combo boxes.
The document discusses different types of nested classes in Java - member inner classes, anonymous inner classes, and local inner classes. It provides examples of each type of nested class and how they can access members of the outer class. Method overloading is also covered, explaining how methods can be overloaded by changing parameters and return types. The key differences between passing objects and primitives by value and reference are explained.
Objects are instances of classes in C++. An object is created by declaring a variable of a class type, which allocates memory for that object. Multiple objects can be created from a single class. Class members can be accessed and modified using the dot operator and object name. Arrays of objects are also possible. Objects can be passed as arguments to functions by value or by reference.
This document provides an overview of classes in Java. It discusses key concepts like class templates, objects, fields, methods, access modifiers, constructors, static members, and class design best practices. Specifically, it defines a class as a template for objects that encapsulates data and functions, and notes that objects are instances of classes. It also explains how to declare fields and methods, the different access levels for class members, and how to define constructors including overloaded and parameterized constructors.
This document contains slides from a lecture on classes and objects in Java. It discusses key concepts like class abstraction, encapsulation, instance variables, constructors, methods, visibility modifiers, and more. An example class discussed is Clock, which represents a 12-hour clock and defines its internal state (hours, minutes, seconds) and interface (get/set time methods).
This document contains slides from a lecture on classes and objects in Java. It discusses key concepts like class abstraction, encapsulation, constructors, instance variables, methods and scope. Specifically, it uses examples of a Clock and Turtle class to illustrate how to define the internal state and behaviors of an object using a class. The relationship between classes and objects is analogous to blueprints and real objects built from them. Methods can access and modify an object's internal state.
Java classes provide templates for objects with methods and fields. Classes can contain static methods and fields that are shared across all instances, as well as instance methods and fields that are unique to each object. Arrays are objects that hold multiple elements of a single type, accessed via integer indices starting from 0. Comments provide documentation for code via javadoc comments or single-line comments. Constructors initialize new objects and can overload based on argument types. Methods define reusable blocks of code that may return values or not.
This document discusses classes and objects in Java. It defines a class as a blueprint for creating objects, with classes containing variables, methods, constructors and other elements. An object is an instance of a class. The document provides examples of creating Box and Person classes, with objects of each class being instantiated and their variable values displayed. It also shows how to represent a class in UML notation and provides an example of writing Java code based on a UML class diagram.
Classes and objects are fundamental concepts in object-oriented programming. A class defines the properties and behaviors of a type of object, acting as a blueprint. An object is an instance of a class, which is created at runtime and has state and behavior. The lecture discusses these concepts and provides examples of defining classes for boxes and students, then creating objects and setting their property values. It also shows how to represent classes using UML diagrams and write Java code from UML class diagrams.
This document provides an overview of object-oriented programming concepts in Java, including classes, objects, variables, methods, constructors, abstraction, encapsulation, inheritance, and polymorphism. It defines classes and objects, and describes how classes act as blueprints for objects. It explains the syntax for defining classes and class members like variables and methods. It also covers method overloading, different types of methods, and how constructors are used to initialize objects. The document concludes with brief explanations of abstraction, encapsulation, inheritance, and polymorphism as fundamental principles of object-oriented design.
1. Object Oriented Solutions
(Objects & Classes)
Instructor: Dr. Tabassam Nawaz
Class Timings:
3:00p.m. 6:00p.m. WED
2. Classes & Objects
• CLASS
– At core of JAVA
– Logical construct
– Defines shape and nature of an object
– Forms the basis for OOP
– Defines a new data type
– Template of an object
Object Oriented Solution (Spring 2009) UET Taxila 2 / 46
3. Classes & Objects
• OBJECT:
– An instance of a class
– Physical reality
– Occupies space in memory
Object Oriented Solution (Spring 2009) UET Taxila 3 / 46
4. The General Form of a Class
• class classname {
type instance-variable1;
type instance-variable2;
//…
type instance-variableN;
type methodname1(parameter-list) {
// body of method }
type methodname2(parameter-list) {
// body of method }
//…
type methodnameN(parameter-list) {
// body of method }
}
Object Oriented Solution (Spring 2009) UET Taxila 4 / 46
5. The General Form of a Class
• Data or variable defined within the class
are called Instance Variable.
• The code is contained within methods.
• Both are Members of the class.
• Each object contains its own copy of
variables.
Object Oriented Solution (Spring 2009) UET Taxila 5 / 46
6. A Simple Class
• class Box {
double width;
double height;
double depth;
}
// Box is a new data type.
Object Oriented Solution (Spring 2009) UET Taxila 6 / 46
7. Creating an Object
• Box mybox = new Box();
// create a Box object called mybox
// mybox will be an instance of Box
// has physical reality
• mybox.width = 100;
// dot(.) operator to access instance variables as well
as methods within an object.
Object Oriented Solution (Spring 2009) UET Taxila 7 / 46
8. A program that uses the Box class.
/* A program that uses the Box class.
Call this file BoxDemo.java */
class Box {
double width;
double height;
double depth;
}
// This class declares an object of type Box.
class BoxDemo {
public static void main(String args[]) {
Box mybox = new Box();
double vol;
Object Oriented Solution (Spring 2009) UET Taxila 8 / 46
9. A program that uses the Box class.
(contd…)
// assign values to mybox's instance variables
mybox.width = 10;
mybox.height = 20;
mybox.depth = 15;
// compute volume of box
vol = mybox.width * mybox.height * mybox.depth;
System.out.println("Volume is " + vol);
}
}
Object Oriented Solution (Spring 2009) UET Taxila 9 / 46
10. Output
• Call the file BoxDemo.java
• Two .class files have been created
• Both classes can be in their own files.
• Volume is 3000.0 //output of program
Object Oriented Solution (Spring 2009) UET Taxila 10 / 46
11. Two Box Objects
// This program declares two Box objects.
class Box {
double width;
double height;
double depth;
}
class BoxDemo2 {
public static void main(String args[]) {
Box mybox1 = new Box();
Box mybox2 = new Box();
double vol;
// assign values to mybox1's instance variables
mybox1.width = 10;
mybox1.height = 20;
mybox1.depth = 15;
Object Oriented Solution (Spring 2009) UET Taxila 11 / 46
12. Two Box Objects (contd…)
/* assign different values to mybox2's
instance variables */
mybox2.width = 3;
mybox2.height = 6;
mybox2.depth = 9;
// compute volume of first box
vol = mybox1.width * mybox1.height * mybox1.depth;
System.out.println("Volume is " + vol);
// compute volume of second box
vol = mybox2.width * mybox2.height * mybox2.depth;
System.out.println("Volume is " + vol);
}
}
Object Oriented Solution (Spring 2009) UET Taxila 12 / 46
13. Output
• Volume is 3000.0
Volume is 162.0 //output of program
• Mybox1’s data is completely separate
from the data contained in mybox2.
Object Oriented Solution (Spring 2009) UET Taxila 13 / 46
14. Declaring Objects
• Two-step process:
– Must declare a variable of class type.
// This variable does not define an object but can refer to an object.
– Must acquire an actual, physical copy of the object
and assign it to that variable.
// using new operator
• new operator dynamically allocates memory for
an object and returns a reference to it.
// reference (stored in the variable) = address in memory of the object.
Object Oriented Solution (Spring 2009) UET Taxila 14 / 46
15. Declaring Objects
• Box mybox = new Box();
// combines the two steps.
• Box mybox;
// declare reference to object.
mybox = new Box();
// allocate a Box object.
Object Oriented Solution (Spring 2009) UET Taxila 15 / 46
16. Output
• After declaring reference to mybox, it
contains the value null ( does not yet point
to an actual object).
• mybox simply holds the memory address
of the actual Box object.
Object Oriented Solution (Spring 2009) UET Taxila 16 / 46
18. new Operator
• Dynamically allocates memory for an object.
• General form
class-var = new classname();
// class-var is a variable of class type being
created. The classname is the name of the class
that is being instantiated. () for constructor. If
there is no explicit constructor is specified, Java
will automatically define a default constructor.
Object Oriented Solution (Spring 2009) UET Taxila 18 / 46
19. new Operator
• Java’s simple data types are not
implemented as objects but as normal
variables in the interest of efficiency.
• Object versions of simple data types are
also available.
Object Oriented Solution (Spring 2009) UET Taxila 19 / 46
20. new Operator
• new allocates memory for an object during
runtime as our program can create as
many or as few objects as it needs.
• Memory is finite.
• For insufficient memory, a runtime
exception will occur.
Object Oriented Solution (Spring 2009) UET Taxila 20 / 46
21. Assigning Object Reference
Variables
• Box b1 = new Box();
Box b2 = b1;
width
b1
height
depth
b2
• The assignment of b1 to b2 did not
allocate any memory or copy any part of
the original object.
Object Oriented Solution (Spring 2009) UET Taxila 21 / 46
22. Assigning Object Reference
Variables
• Any changes made to the object through b2 will
affect the object to which b1 is referring.
• A subsequent assignment to b1 will simply
unhook b1 from the original object without
affecting the object or b2.
• Box b1 = new Box();
Box b2 = b1;
//…
b1 = null;//b2 still points to the original object.
Object Oriented Solution (Spring 2009) UET Taxila 22 / 46
23. Introducing Methods
• General form
type name (parameter-list){
// body of method
}
type= returned type (may be void)
name = name of method
Parameter-list = sequence of types and identifier
pairs separated by commas.
• return value; // return statement must be
included if the return type is other than void.
Object Oriented Solution (Spring 2009) UET Taxila 23 / 46
24. Adding a Method to the Box Class
• Methods define the interface to most
classes.
• This allows the class implementer to hide
the specific layout of internal data
structure behind cleaner method
abstractions.
Object Oriented Solution (Spring 2009) UET Taxila 24 / 46
25. Program includes a method inside
the Box Class
// This program includes a method inside the box class.
class Box {
double width;
double height;
double depth;
// display volume of a box
void volume() {
System.out.print("Volume is ");
System.out.println(width * height * depth);
}
}
class BoxDemo3 {
public static void main(String args[]) {
Box mybox1 = new Box();
Box mybox2 = new Box();
Object Oriented Solution (Spring 2009) UET Taxila 25 / 46
26. Program includes a method inside
the Box Class (contd…)
// assign values to mybox1's instance variables
mybox1.width = 10;
mybox1.height = 20;
mybox1.depth = 15;
/* assign different values to mybox2's
instance variables */
mybox2.width = 3;
mybox2.height = 6;
mybox2.depth = 9;
// display volume of first box
mybox1.volume();
// display volume of second box
mybox2.volume();
}
}
Object Oriented Solution (Spring 2009) UET Taxila 26 / 46
27. This program includes a method
inside the Box Class
• Each time volume() is invoked, it displays the
volume for the specified box.
• When an instance variable is accessed by code
that is not part of the class in which that instance
variable is defined, it must be done through an
object, by use of the dot operator. However,
when an instance variable is accessed by code
that is part of the same class as the instance
variable, that variable can be referred to directly.
The same thing applies to methods.
Object Oriented Solution (Spring 2009) UET Taxila 27 / 46
28. Returning a Value
// Now, volume() returns the volume of a box.
class Box {
double width;
double height;
double depth;
// compute and return volume
double volume() {
return width * height * depth;
}
}
class BoxDemo4 {
public static void main(String args[]) {
Box mybox1 = new Box();
Box mybox2 = new Box();
double vol;
Object Oriented Solution (Spring 2009) UET Taxila 28 / 46
29. Returning a Value (contd…)
// assign values to mybox1's instance variables
mybox1.width = 10;
mybox1.height = 20;
mybox1.depth = 15;
/* assign different values to mybox2's
instance variables */
mybox2.width = 3;
mybox2.height = 6;
mybox2.depth = 9;
// get volume of first box
vol = mybox1.volume();
System.out.println("Volume is " + vol);
// get volume of second box
vol = mybox2.volume();
System.out.println("Volume is " + vol);
}
}
Object Oriented Solution (Spring 2009) UET Taxila 29 / 46
30. Returning a Value
• The type of data returned by a method
must be compatible with the return type
specified by the method.
• The variable receiving the value returned
by a method must also be compatible with
the return type specified.
• Actually no need for vol variable:
System.out.println("Volume is " + mybox1.volume());
Object Oriented Solution (Spring 2009) UET Taxila 30 / 46
31. Adding a Method that takes
Parameters
• int square(){
return 10 * 10;
}
• int square(int i){
return i * i;
}
Object Oriented Solution (Spring 2009) UET Taxila 31 / 46
32. Parameter Vs Argument
• A parameter is a variable defined by a
method that receives a value when the
method is called.
• An argument is a value that is passed to
a method when it is invoked.
Object Oriented Solution (Spring 2009) UET Taxila 32 / 46
33. program uses a parameterized
method
// This program uses a parameterized method.
class Box {
double width;
double height;
double depth;
// compute and return volume
double volume() {
return width * height * depth;
}
// sets dimensions of box
void setDim(double w, double h, double d) {
width = w;
height = h;
depth = d;
}
}
Object Oriented Solution (Spring 2009) UET Taxila 33 / 46
34. program uses a parameterized
method (contd…)
class BoxDemo5 {
public static void main(String args[]) {
Box mybox1 = new Box();
Box mybox2 = new Box();
double vol;
// initialize each box
mybox1.setDim(10, 20, 15);
mybox2.setDim(3, 6, 9);
// get volume of first box
vol = mybox1.volume();
System.out.println("Volume is " + vol);
// get volume of second box
vol = mybox2.volume();
System.out.println("Volume is " + vol);
}
}
Object Oriented Solution (Spring 2009) UET Taxila 34 / 46
35. Constructors
• Tedious to initialize all the variables in a
class each time an instance is created.
• Automatic initialization is performed
through the use of a constructor.
• A constructor initializes an object
immediately upon creation.
• Same name as class name
• No return type not even void.
Object Oriented Solution (Spring 2009) UET Taxila 35 / 46
36. Constructors
/* Here, Box uses a constructor to initialize the dimensions of a box. */
class Box {
double width;
double height;
double depth;
// This is the constructor for Box.
Box() {
System.out.println("Constructing Box");
width = 10;
height = 10;
depth = 10;
}
// compute and return volume
double volume() {
return width * height * depth;
}
}
Object Oriented Solution (Spring 2009) UET Taxila 36 / 46
37. Constructors (contd…)
class BoxDemo6 {
public static void main(String args[]) {
// declare, allocate, and initialize Box objects
Box mybox1 = new Box();
Box mybox2 = new Box();
double vol;
// get volume of first box
vol = mybox1.volume();
System.out.println("Volume is " + vol);
// get volume of second box
vol = mybox2.volume();
System.out.println("Volume is " + vol);
}
}
Object Oriented Solution (Spring 2009) UET Taxila 37 / 46
39. Default Constructor
• When we do not explicitly define a
constructor for a class, then Java creates
a default constructor for the class.
• The default constructor automatically
initializes all instance variables to zero.
• Once we define our own constructor, the
default constructor is no longer used.
Object Oriented Solution (Spring 2009) UET Taxila 39 / 46
40. Parameterized Constructors
• Previously, all boxes have the same
dimensions.
• A way to construct Box objects of various
dimensions.
• Adding parameters is much more useful.
Object Oriented Solution (Spring 2009) UET Taxila 40 / 46
41. Parameterized Constructors
/* Here, Box uses a parameterized constructor to
initialize the dimensions of a box. */
class Box {
double width;
double height;
double depth;
// This is the constructor for Box.
Box(double w, double h, double d) {
width = w;
height = h;
depth = d;
}
// compute and return volume
double volume() {
return width * height * depth;
}
}
Object Oriented Solution (Spring 2009) UET Taxila 41 / 46
42. Parameterized Constructors
(contd…)
class BoxDemo7 {
public static void main(String args[]) {
// declare, allocate, and initialize Box objects
Box mybox1 = new Box(10, 20, 15);
Box mybox2 = new Box(3, 6, 9);
double vol;
// get volume of first box
vol = mybox1.volume();
System.out.println("Volume is " + vol);
// get volume of second box
vol = mybox2.volume();
System.out.println("Volume is " + vol);
}
}
Object Oriented Solution (Spring 2009) UET Taxila 42 / 46
44. Lab Session
• Create a class called Date.
• Class Date includes three pieces of information as instance
variables--- a month (type int), a day (type int) and a year
(type int).
• Your class should have a constructor that initializes the three
instance variables and assumes that the values provided are
correct.
• Provide a set and a get method for each instance variable.
• Provide a method named displayDate that display the month,
day and year separated by forward slahes (/).
• Write a test application named DateTest that demonstrates
class Date’s capabilities.
Object Oriented Solution (Spring 2009) UET Taxila 44 / 46
45. Assignment # 3 (Q1)
• Create a class called Invoice that a hardware store might use to
represent an invoice for an item sold at the store.
• An Invoice should include four pieces of information as instance
variables--- a part number (type String), a part description (type
String), a quantity of the item being purchased (type int) and a price
per item (type double).
• Your class should have a constructor that initializes the four
instance variables.
• Provide a set and a get method for each instance variable.
• In addition, provide a method named getInvoiceAmount that
calculates the invoice amount (i.e. multiplies the quantity by the
price per item), then returns the amount as double value.
• If the quantity is not positive, it should be set to zero.
• If the price per item is not positive, it should be set to 0.0.
• Write a test application named InvoiceTest that demonstrates class
Invoice’s capabilities.
Object Oriented Solution (Spring 2009) UET Taxila 45 / 46
46. Assignment # 3 (Q2)
• Create a class called Employee.
• Class Employee includes three pieces of information as instance
variables--- a first name (type String), a last name (type String) and
a monthly salary (type double).
• Your class should have a constructor that initializes the three
instance variables.
• Provide a set and a get method for each instance variable.
• If the monthly salary is not positive, it should be set to 0.0.
• Write a test application named EmployeeTest that demonstrates
class Employee’s capabilities.
• Create Two Employee’s objects and display each object’s yearly
salary.
• Give each Employee a 10% raise and display each Empolyee’s
yearly salary again.
Object Oriented Solution (Spring 2009) UET Taxila 46 / 46