Deep Dive Into Java

Polymorphism Polymorphism means " Many Forms " - One Object with many behaviors. In other words, ability to appear more than one i.e. to do different things with single object. It can be implemented by method overloading and method overriding in java. For eg. : When you press a device it will turn on, when you press it again it will turn off. Similarly in java "+" Plus Operator has polymorphic behavior: It can perform Arithmetic Operation as well as Concatenation Operation Types of Polymorphism Static Polymorphism Dynamic Polymorphism Static Polymorphism also represented as Compile Time  Polymorphism and Early Binding  Polymorphism. Static Polymorphism is just a method overloading. Thus, it is a process of defining more than one functionalities with same name in same class but having different parameter lists (i.e. different no. of parameters list or different parameters type) Here compiler will figure out which method to call by...

Variables Variables acts as a container for the user data. It is a named area that is allocated by the user and space will be allocated according to its datatype. Variable needs to be declared before using them. Value of variable can be changed any number of times during the execution of program.  For example:                  int a;   //declaring an integer type variable.                  a = 5;  //assigning value to a variable. Local Variables : Variables that are declared inside a members are called Local Variables. Local variables are necessary to initialized.Their value is varied from object to object.           *  Only Final modifier is used with local keywords.           * They can be initialized in static and instance block.           * Stored inside stack memory. ...

Introduction To Java To learn the Java Language... we need to understand WHAT is java, WHERE it is used, WHY we use java. WHAT is java?     Java is a programming language. A language used by humans to communicate with systems. It was created by Sun Microsystems, Inc. in 1991. Sun Microsystems was acquired by the Oracle Corporation in 2010. Now Java is owned by Oracle. WHERE it is used?    Java is used where we need to develop some application which can be Desktop Applications, Web Applications or Mobile based Applications. Desktop application  are stand alone applications. To built these applications in JAVA we need to install the JSE(Java Standard Edition), JDE(Java Distributed Edition). Web  applications are client-server applications. To built these app ,we need to install JEE(Java Enterprise Edition). These applications are accessed using browsers. Mobile applications are also standalone applications, To built them we need JME(Java Mobil...

Operators Operators are used to perform some operations. Operators are special symbols that works with variables and constants in java. These symbols performs specific operation and gave result accordingly. Operators work with Operands. For Eg: a + b; Here a, b are Operands to which operation is to be performed,          + is Operator symbol. To work with operators 3 things must be noticed before using them i.e. Use of operator. Type of operand you are using. Result of operation. Unary Operators   : These type of operators required only one operand. For e:. +, -, ++, -- Binary Operators  : These type of operators required two operands to perform some operation. For eg: +, -, *, =, >, <, && etc. Ternary Operators :  These type of operators required three operands to perform some operation. For eg: :? Arithmetic Operators :           Arithmetic operato...

Literals Literal is the value that we pass in the variables. In other words, Literals are syntactic representation of boolean,numeric,character and string type. These values can be fixed or constant and are stored in the variable. Generally literal are categorized into two types i.e. Numeric Literals and Non Numeric Literals. Integer Literal : They includes - int, short, long, byte. These are the value without any decimal. Int is default type of integer. if any value is out of range in integer literal then compiler will consider that value as int and generates an error. To represent any value in long L/l will be used at the end. There are 4 integer Literals type i.e. Decimal, Octal, Hexadecimal, Binary(added in java 7)  Decimal Literals has base 10 i.e from 0 to 9.          They must not be started with 0. Example :          int a = 111;          it will print 111 Octal...

Keywords Keywords are the words that are already defined in language. They are also known as Reserved Words. They are created for specific use ,their working cannot be changed.In java programming language there are 50 reserved words that have different meaning in java. Initially there are 49 keywords in java till java 1.4 and then "enum" is added with java 1.5 i.e. java 5 keywords are defined in lower case only. keywords cannot be used as a variable, method, class. List of these 50 java keywords are -  abstract       continue       for                        new                       switch assert          default        goto         ...