javadoc tools or API Document

Creating API Document | javadoc tool

We can create document api in java by the help of javadoc tool. In the java file, we must use the documentation comment /**... */ to post information for the class, method, constructor, fields etc

                                      package com.agravatvipul;

/** This class is a user-defined class that contains one methods cube.*/ 

 public class vip

 {

  /** The cube method prints cube of the given number */  

                              public static void  cube(int n)

                                {System.out.println(n*n*n);

             }

  }  

To create the document API, you need to use the javadoc tool followed by java file name. There is no need to compile the javafile.

On the command prompt, you need to write:

javadoc vip.java

to generate the document api. Now, there will be created a lot of html files. Open the index.html file to get the information about the classes.

Read More

SDLC

Read More

JAVA UNICODE SYSTEM

Why java uses Unicode System?

unicode system that use to encoded the byte code .

Before Unicode, there were many language standards:

ASCII (American Standard Code for Information Interchange) for the United States. ISO 8859-1 for Western European Language. KOI-8 for Russian. GB18030 and BIG-5 for chinese, and so on.

This caused two problems: A particular code value corresponds to different letters in the various language standards. The encodings for languages with large character sets have variable length.Some common characters are encoded as single bytes, other require two or more byte.

To solve these problems, a new language standard was developed i.e. Unicode System.

In unicode, character holds 2 byte, so java also uses 2 byte for characters.

lowest value:\u0000

highest value:\uFFFF

Read More

Different java (JVM) (Java Virtual Machine),(JER)java runtime environment,(JDK)Java Development Kit

Difference between JDK, JRE and JVM

Understanding the difference between JDK, JRE and JVM is important in Java. We are having brief overview of JVM here.

If you want to get the detailed knowledge of Java Virtual Machine, move to the next page. 

JVM

JVM (Java Virtual Machine) is an abstract machine. It is a specification that provides runtime environment. it also  bytecode can be executed.

JVMs are available for many hardware and software platforms. JVM platform dependent because configuration of each OS differs. But, Java is platform independent.

The JVM performs following main tasks:

• Loads code
• Verifies code
• Executes code
• Provides runtime environment

JRE

       It is used to provide runtime environment.It is the implementation of JVM. It physically exists. It contains set of libraries + other files that JVM uses at runtime.

Implementation of JVMs are also actively released by other companies besides Sun Micro Systems.

JDK

JDK is an acronym for Java Development Kit.It physically exists.It contains JRE + development tools.

Read More

Class AND Object

java Different between class and object ?

Read More

java and c++

Explain Different between c++ and java

Comparison Index	C++	Java
Platform-independent	C++ is platform-dependent.	Java is platform-independent.
Mainly used for	C++ is mainly used for system programming.	Java is mainly used for application programming. It is widely used in window, web-based, enterprise and mobile applications.
Goto Statement	C++ supports goto statement.	Java doesn't support goto statement.
Multiple inheritance	C++ supports multiple inheritance.	Java doesn't support multiple inheritance through class. It can be achieved by interfaces in java.
Operator Overloading	it  supports operator overloading.	it doesn't support operator overloading.
Pointers	C++ supports pointers. You can write pointer program in C++.	Java supports pointer internally. But you can't write the pointer program in java. It means java has restricted pointer support in java.
Compiler and Interpreter	C++ uses compiler only.	Java uses compiler and interpreter both.
Call by Value and Call by reference	C++ supports both call by value and call by reference.	Java supports call by value only. There is no call by reference in java.
Structure and Union	C++ supports structures and unions.	Java doesn't support structures and unions.
Thread Support	C++ doesn't have built-in support for threads. It relies on third-party libraries for thread support.	Java has built-in thread support.
Documentation comment	C++ doesn't support documentation comment.	Java supports documentation comment (/** ... */) to create documentation for java source code.
Virtual Keyword	C++ supports virtual keyword so that we can decide whether or not override a function.	Java has no virtual keyword. We can override all non-static methods by default. In other words, non-static methods are virtual by default.
unsigned right shift >>>	C++ doesn't support >>> operator.	Java supports unsigned right shift >>> operator that fills zero at the top for the negative numbers. For positive numbers, it works same like >> operator.

Read More

Operators in java

Operator in java is a symbol that is used to perform operations. There are many types of operators in java such as unary operator, arithmetic operator, relational operator, shift operator, bitwise operator, ternary operator and assignment operator.

Operators                                             Precedence multiplicative * / % additive + - shift << >> >>> relational < > <= >= instanceof equality == != bitwise AND & bitwise exclusive OR ^ bitwise inclusive OR | logical AND && logical OR || ternary ? : assignment = += -= *= /= %= &= ^= |= <<= >>= >>>=

Read More