Flashcards on Introduction to Object Oriented Programming in Java
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What is Object Oriented Programming?
Object-oriented programming (OOP) is a programming paradigm based on the concept of 'objects', which can contain data and code, in the form of fields and methods respectively. In Java, everything is treated as an object.
What are the four basic concepts of Object Oriented Programming in Java?
The four basic concepts of Object Oriented Programming in Java are abstraction, encapsulation, inheritance, and polymorphism.
What is Abstraction in Object Oriented Programming in Java?
Abstraction is the concept of hiding the implementation details and displaying only the necessary information to the user. It allows the user to work with the high-level implementation while ignoring the low-level implementation.
What is Encapsulation in Object Oriented Programming in Java?
Encapsulation is the process of binding the data and code together and preventing direct access to data from the outside world. It helps in data hiding and thus provides security to the data.
What is Inheritance in Object Oriented Programming in Java?
Inheritance is the process of creating new classes from the existing classes by inheriting the properties and methods of the parent class. It allows the reuse of code and helps in implementing polymorphism in Java.
What is Polymorphism in Object Oriented Programming in Java?
Polymorphism is the concept of using a single name or method to represent multiple forms. In Java, it can be achieved through method overloading and method overriding.
What is a Class in Java?
A class in Java is a template or blueprint for creating objects. It defines the properties and methods that the objects of that class will have.
What is an Object in Java?
An object in Java is an instance of a class. It is a real-world entity that has state (variables) and behavior (methods).
What is a Constructor in Java?
A constructor in Java is a special method that is used to initialize the object of a class. It has the same name as the class and does not have a return type.
What is a Method in Java?
A method in Java is a block of code that performs a specific task. It is used to encapsulate the code and can be invoked using the object of the class.
What is a Variable in Java?
A variable in Java is a type of data storage location that holds a value. It is declared with a data type and can be assigned a value during initialization or later in the code.
What is a Data Type in Java?
A data type in Java is a classification of data into different types based on its nature and use. Some of the commonly used data types in Java are int, float, double, char, boolean, etc.
What is an Access Modifier in Java?
An access modifier in Java is a keyword that is used to set the accessibility of a class, method, variable, or constructor. There are four types of access modifiers in Java: public, private, protected, and default.
What is the difference between an Interface and a Class in Java?
An Interface in Java is a model of how something works, whereas a Class in Java is an implementation of that model. An interface in Java contains only method declarations and constants, while a class contains properties, methods, and constructors.
What is a Package in Java?
A package in Java is a collection of related classes and interfaces that are grouped together. It helps in organizing the code and avoids naming conflicts by providing a unique namespace for the classes and interfaces.
What is Object Oriented Programming?
Object-oriented programming (OOP) is a programming paradigm based on the concept of 'objects', which can contain data and code, in the form of fields and methods respectively. In Java, everything is treated as an object.
What are the four basic concepts of Object Oriented Programming in Java?
The four basic concepts of Object Oriented Programming in Java are abstraction, encapsulation, inheritance, and polymorphism.
What is Abstraction in Object Oriented Programming in Java?
Abstraction is the concept of hiding the implementation details and displaying only the necessary information to the user. It allows the user to work with the high-level implementation while ignoring the low-level implementation.
What is Encapsulation in Object Oriented Programming in Java?
Encapsulation is the process of binding the data and code together and preventing direct access to data from the outside world. It helps in data hiding and thus provides security to the data.
What is Inheritance in Object Oriented Programming in Java?
Inheritance is the process of creating new classes from the existing classes by inheriting the properties and methods of the parent class. It allows the reuse of code and helps in implementing polymorphism in Java.
What is Polymorphism in Object Oriented Programming in Java?
Polymorphism is the concept of using a single name or method to represent multiple forms. In Java, it can be achieved through method overloading and method overriding.
What is a Class in Java?
A class in Java is a template or blueprint for creating objects. It defines the properties and methods that the objects of that class will have.
What is an Object in Java?
An object in Java is an instance of a class. It is a real-world entity that has state (variables) and behavior (methods).
What is a Constructor in Java?
A constructor in Java is a special method that is used to initialize the object of a class. It has the same name as the class and does not have a return type.
What is a Method in Java?
A method in Java is a block of code that performs a specific task. It is used to encapsulate the code and can be invoked using the object of the class.
What is a Variable in Java?
A variable in Java is a type of data storage location that holds a value. It is declared with a data type and can be assigned a value during initialization or later in the code.
What is a Data Type in Java?
A data type in Java is a classification of data into different types based on its nature and use. Some of the commonly used data types in Java are int, float, double, char, boolean, etc.
What is an Access Modifier in Java?
An access modifier in Java is a keyword that is used to set the accessibility of a class, method, variable, or constructor. There are four types of access modifiers in Java: public, private, protected, and default.
What is the difference between an Interface and a Class in Java?
An Interface in Java is a model of how something works, whereas a Class in Java is an implementation of that model. An interface in Java contains only method declarations and constants, while a class contains properties, methods, and constructors.
What is a Package in Java?
A package in Java is a collection of related classes and interfaces that are grouped together. It helps in organizing the code and avoids naming conflicts by providing a unique namespace for the classes and interfaces.