Fifth Program | Factorial | Java Class 6

This video guide how to write sixth Program called Factorial calculator in Java, compile it and finally run it by the basic method command prompt
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#JavaProgram #JavaTutorials
EXPLANATION OF EACH TERM IN ABOVE PROGRAM :

1) class :
- class is a keyword.
- Java is an object oriented programming and you cannot run your code without
a class in Java. So you need to put your code inside a class.

-In one java program, there can be only single public class.
i)Syntax of class :
access-modifier class ClassName
{
//body
}

-If a class has no modifier (the default, also known as package-private), it is visible
only within its own package (you will learn about them in a later episodes)

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class Abc :
- Abc is an Identifier (user-defined class name)
-Class-name should follow the rules of an identifier.

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public ststic void main(String args[])


public :
-public is access modifier keyword.
-JVM can be installed anywhere i.e. C or D or any other drive and JVM is
responsible to call main method which may be in any other drive, thus to
call main method by JVM from anywhere, “main” method should be declared
public.



static :
-static is keyword.

-At the time of execution there is no object, thus by declaring main method
as static, it becomes class level method (not object level method), so it can
be called without object (JVM class main method). Thus main method
no where related to object.


void :
-void is return type keyword.
-void means nothing or empty.
-main method has void return type as it does not return anything to JVM.
If it returns then what will JVM do with the value, it will be of no use.

main() :
- main is predefined method, which is configured inside JVM.
-JVM always start its execution from main method.


(String[] args) :
- command-line arguments

We can declare “String[] args” in any acceptable form, which are given below :-
i) String[] args
ii) String []args
iii) String args[]

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System :
- Predefined class present in “java.lang” package.

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out :
- out is a “static variable”of “PrintStream” class present in “System” class.

Three static variables of PrintStram class are :
- out (for output)

- in (for input)

- err (for error)

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println() :
- println() is method of PrintStram class.

Three different methods of PrintStream class to print on console are :
- print()

- println()

- printf()

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