Java Programming Language Features and Syntax Classes Objects and Inheritance Classes are user defined blueprints or templates from which objects are created Objects are instances of a class Inheritance is a process in which one class acquires the properties methods and fields of another The class which inherits the properties of other is called subclass derived class child class The class whose properties are inherited is called superclass base class parent class Operators and Expressions in Java Operators are symbols that tell the Java compiler to perform specific mathematical or logical manipulations Expressions are used to represent a computation in Java Java Support Arithmetic Relational Logical Bitwise Assignment and Miscellaneous Operators Control Statements and Decision Making Java control statements are categorized into three decision making selection and iteration statements Decision making statements are further divided into if if else nested if switch Selection statements are used to select one branch for execution from many Iteration statements are used to execute a block of code repeatedly An array is a collection of variables that are accessed with an index number Arrays and Collections in Java Arrays are objects in Java A collection is an object that represents a group of objects known as its elements Some collection classes are List Set Queue Map Functions and Methods in Java Functions in Java are also known as methods and a group of related methods is known as a class Method is a block of code which can be called by a program whenever required Methods might or might not return a value Methods might or might not take parameters The method s behavior doesn t depend on the place from where it is called Inheritance Polymorphism and Encapsulation Inheritance is a process in which one class acquires the properties methods and fields of another Polymorphism The ability of an object to take on multiple forms The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object Encapsulation is the mechanism of hiding the internal details or mechanics of how an object does something Java uses the keyword private to hide the fields in a class from other classes