Found 9326 Articles for Object Oriented Programming

Following are various methods of Object class −protected Object clone() - Used to create and return a copy of this object. boolean equals(Object obj) - Used to indicate whether some other object is "equal to" this one.protected void finalize() - garbage collector calls this method on an object when it determines that there are no more references to the object.Class getClass() - Used to get the runtime class of this Object.int hashCode() - Used to get a hash code value for the object.void notify() - Used to wake up a single thread that is waiting on this object's monitor.void notifyAll() - ... Read More

Yes, an overridden method can have a different access modifier but it cannot lower the access scope.The following rules for inherited methods are enforced -Methods declared public in a superclass also must be public in all subclasses.Methods declared protected in a superclass must either be protected or public in subclasses; they cannot be private.Methods declared private are not inherited at all, so there is no rule for them.

Classes are the fundamental building blocks of Java. It is a programmable template that can be expanded upon, and it determines the form and characteristics of an item. One may say that a class is the most fundamental component of an object oriented programming language like Java. Each and every idea that will be put into action by means of a Java application must first be encased inside of a class. In object-oriented programming, the fundamental building blocks are called classes objects.Variables and methods are the building blocks of a Java class. Instance variables are the terms used to refer ... Read More

Yes! Java supports constructor overloading. In constructor loading, we create multiple constructors with the same name but with different parameters types or with different no of parameters.ExampleLive Demopublic class Tester {      private String message;      public Tester(){       message = "Hello World!";    }    public Tester(String message){       this.message = message;    }      public String getMessage(){       return message ;    }      public void setMessage(String message){       this.message = message;    }      public static void main(String[] args) {       Tester tester = new Tester();       System.out.println(tester.getMessage());           Tester tester1 = new Tester("Welcome");       System.out.println(tester1.getMessage());      } }   OutputHello World! Welcome

Anonymous object in Java means creating an object without any reference variable. Generally, when creating an object in Java, you need to assign a name to the object. But the anonymous object in Java allows you to create an object without any name assigned to that object. So, if you want to create only one object in a class, then the anonymous object would be a good approach. Reading this article, you will learn what an anonymous object is and how to create and use anonymous objects in Java. Let's get started! Anonymous Object in Java Anonymous means Nameless. An ... Read More

You can create a List of object easily. Consider the following example, where I'll create an array of Employee objects and print their details in a for loop. import java.lang.reflect.InvocationTargetException; import java.util.ArrayList; import java.util.List; public class Tester implements Cloneable { private int data; public int getData() { return data; } public void setData(int data) { this.data = data; } public Tester(int data){ ... Read More

Consider a class Tester which has implemented Cloneable interface. Now you can initialize an object using following five ways:1. Using new keyword.Tester tester1 = new Tester();2. Using Class.forName() methodTester tester2 = (Tester)Class.forName("Tester").newInstance();3. Using clone method.Tester tester3 = tester1.clone();4. Using Constructor.forName() methodTester tester4 = Tester.class.getConstructor().newInstance();5. Using DeserializationObjectInputStream objectInputStream = new ObjectInputStream(inputStream ); Tester tester5 = (MyObject) objectInputStream.readObject(); Using new keyword is the most preferred one.

Consider a class Tester which has implemented Cloneable interface. Now you can initialize an object using following three ways −1. Using new keyword.Tester tester1 = new Tester();2. Using Class.forName() methodTester tester4 = (Tester)Class.forName("Tester").newInstance();3. Using clone method.Tester tester2 = tester1.clone();

Yes, it is similar to a new keyword of C++. a new keyword is used to initialize/create an object. See the following example −Employee employee = new Employee();Here new keyword is used to create an object of class Employee.new Employee() invokes the constructor of the class Employee.new keyword can also be used without assigning the object to a reference variable. See the example −String name = new Employee().getName();Here we are creating an object using new keyword and then invoked a method getName() on the object and passed the result to a variable.

Java follows camel casing for objects, class, variables etc. If a name is having multiple words, the first letter is small then consecutive words are joint with the first letter as a capital case. Consider the following example − Taxation Department Class - TaxationDepartment Object - taxationDepartment Method - getTaxationDepartmentDetails Variable - taxationDepartment