Use of ' this ' keyword in Java

 How to use ' this ' keyword in java?

class A

{

    public int x;

    A()

    {

        x=0;

        System.out.println("Default Constructor");

    }

    A(int x)

    {

        this.x=x;

        System.out.println("I am THIS.X");

    }

}

public class UseofThis{

    public static void main(String[] args) {

        A ob1=new A();

        A ob2=new A(5);

    }

}

Use of Scanner Class in Java

SCANNER CLASS: 

Example 1:

import java.util.Scanner;

public class ScannerEg1 {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a number");

        int a = sc.nextInt();

        double sq = a * a;

        double rem = sq % 10;

        System.out.println("square is" + sq);

        System.out.println("Last Digit is" + rem);

    }

}

Example 2:

import java.util.*;

public class ScannerEg2 {

    public static void main(String[] args) {

        int n, sq, rem;

        Scanner sc = new Scanner(System.in);

        System.out.println("enter a number");

        n = sc.nextInt();

        sq = n * n;

        System.out.println(sq);

        rem = sq % 10;

        System.out.println(rem);

        if (n == rem) {

            System.out.println("equal");

        } else {

            System.out.println("not equal");

        }

    }

}

Static function in java

How to call a method in main without creating object in Java ?

public class Staticfunc {

    static void f()          //Static keyword is used as the f() is called in main method without object.

    {

        System.out.println("Sunday");

    }

    public static void main(String[] args) {

        System.out.println("Monday");

        f();

        System.out.println("friday");

    } 

Non-static Function in JAVA

How to call a function in main by creating object in java ?

 public class NonStaticFunc {

    void f()

    {

        System.out.println("Sunday");

    }

    public static void main(String[] args) {

        NonStaticFunc ob=new NonStaticFunc();

        System.out.println("Monday");

        ob.f();

        System.out.println("Friday");

    }

}

// Static keyword is not used here as object is created.//

Function Overloading using JAVA ( Method 2 )

 class Func

{

   void f()

    {

        System.out.println("this is without parameter");

    }

    void f(int x)

    {

        System.out.println("this is integer parameter");

    }

    void f(float x)

    {

        System.out.println("this is float parameter");

    }

    void f(char x)

    {

        System.out.println("this is character parameter");

    }

}

public class FunctionOverloading2 {

    public static void main(String[] args) {

         Func ob=new Func();

         ob.f();

        ob.f(5);

        ob.f(10.5f);

        ob.f('a');

    }

}

Function Overloading using JAVA ( Method 1 )

 public class FunctionOverloading1 {

    void f()

    {

        System.out.println("this is without parameter");

    }

    void f(int x)

    {

        System.out.println("this is integer parameter");

    }

    void f(double x)

    {

        System.out.println("this is double parameter");

    }

    void f(char x)

    {

        System.out.println("this is character parameter");

    }

    public static void main(String[] args) {

        FunctionOverloading1 ob=new FunctionOverloading1();

        ob.f();

        ob.f(5);

        ob.f(10.5);

        ob.f('a');

    }

}

Factorial Program using JAVA

 public class Factorial {

    public static void main(String[] args) {

        int i,factorial=1,number=5;

        for(i=1;i<=number;i++)

        {

            factorial=factorial*i;

        }

        System.out.println("Factorial of "+number+" is "+factorial);

    }

}