Java Post1-Introducing programming structure of JAVA

·         Basically we are learning java through programming but for understanding we are defining some terms in Java.

·         So starting small history Java was developed in 1995 by James Gosling and three more at Sun Microsystems but now it is owned by Oracle Corporation.

·         Now starting with our programming manner structure of Java Program…

Structure of JAVA Program

//Program for test

Import java.lang.*;

Class Test

{

                /**

                @author Student

                **/

                public static void main(String argd[])

                {

                                System.out.println(“---------Test----------”);

                }

}

Starting with every programming language we have seen ‘Hello World’ program but behind every program what actually is we will be looking for that.

Now in above program,

·         “//” Comments

·         “import”  is keyword.

·         “java”   is package.

·         “lang” is sub package

·         “*” represents all classes and interfaces in that package

·         “Class” is also keyword.

·         “Test”  is identifier(Name of class).

·         “ public“ is access modifier.

·         “static “ is modifier.

·         “void“ is return type of main method.

·         “String” is predefined class.

·         “args[]“ is array of object reference.

·         “System” is library class.

·         “out” is object reference.

·         “println” is predefined method.

·         “-------Test---------” is string literal.

So this is only we have introduced in program what is but what is actual functionality of each we will be learning in next sessions…

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Java Post2-Declaration of Java file

·         Starting with our source file of java in which we are writing our java code.

·         Java source file saved with .java extension.

·         Some rules while declaring the source file as follows,

ü  A source file can have only one public class.

ü  Source file can have any number of non-public classes

ü  If the source file contains public class then file name must match with public class name.

ü  If the source file does not contain public class then there is no naming restrictions to file name.

Example

1)      X.java public Class X { ===========               }	3)      Y.java public Class Y { ============           }
2)        Z.java Class A { ========                  } Class B { ======== }	4)      R.java  Class Z { ============ }  Class Y { ============= }

NOTE: For every source file of java .class file will be generated.

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Java post3-Starting with comments

·         Starting with details of our java programming structure.

·         First is comments.

·         Comments are used in programming for textual description of code.

·         Comments are always ignored by compiler.

·         Writing comments in programming is optional but for our better understanding of we are writing.

·         Comments are of three types and they are

ü  Single line comments

Syntax:    //-----------------------------------

ü  Multiple line comments

Syntax:             /*-------------------

-----------------*/

ü  Documentation comments

Syntax:      /**----------------

          -------------------

          -------------------*/

        Program: