13. Input Double

import java.io.*;
import java.util.*;
class doublee
{
  public static void main(String args[])
  {
    Scanner scan = new Scanner(System.in);
      System.out.print("Input Integer: ");
    int I = scan.nextInt();
    System.out.print("Input Double(Float no): ");
    double f = scan.nextDouble();
    System.out.println(I);
    System.out.println(f);
 }
}

12. divde two number in java

class div
{
public static void main(String a[])
 {
  int a1=6,b=2,c=0;
  c=a1/b;

System.out.println("c="+c);
}
}

11. Concat two Strings in java

class concat
{
public static void main(String a[])
{

    String s1="  hello  ";
    String s2="  world  ";

    System.out.println(s1);
    System.out.println(s2);

    String s3=s1.concat(s2);
    System.out.println(s3);


    String s4=s1.trim();
    System.out.println(s4);

    String s5=s2.trim();
    System.out.println(s5);

   

    String s6=s4.concat(s5);
    System.out.println(s6);
   
    System.out.println();
    String s7;
    s7=s6.replace('l','t');
    System.out.println(s7);
   
    String s7;
    s7=s6.replace('l','t');
    System.out.println(s7);


    System.out.println(s6.substring(3));
    System.out.println(s6.substring(3,6));

    System.out.println(s6.toLowerCase());

    System.out.println(s6.toUpperCase());

    System.out.println(s6.lastIndexOf('w'));
    System.out.println(s6.lastIndexOf("ll"));

}
}

10. Float Input in java

class circle
{
    public static void main(String a1[])
    {
      double r;
         float pi=3.14f;
        double area=0;

        r=Double.parseDouble(a1[0]);
        area=pi*r*r;
   
      System.out.println("Area of circle is: "+area);
    }
}

9. String Input in java

class buffer
{
public static void main(String a[])
{
StringBuffer sb=new StringBuffer(5);
sb="computer";
System.out.println(sb);
}
}

8. String input in java.,..

class buff
{
public static void main(String a[])
{
    StringBuffer sb=new StringBuffer("computer");
    System.out.println(sb);
    System.out.println();
    System.out.println(sb);
    System.out.println(sb.length());
   System.out.println(sb.capacity());
   System.out.println(sb);
   sb.setLength(5);
   System.out.println(sb);
System.out.println();
System.out.println(sb.charAt(3));
StringBuffer s=new StringBuffer("computer");
System.out.println(s);
System.out.println();
System.out.println(s);
s.setCharAt(1,'a');
System.out.println(s);
System.out.println();
s.insert(5,"FAST");
System.out.println(s);
}
}

7. Float input in java program.

class Area
{
    public static void main (String[] args) {
        float pi=3.142f;
        float area,r;
        r=Float.parseFloat(args[0]);
        area=pi*r*r;
        System.out.println("Area Of Circle: "+area);
    }
}

6. addition of two number using keybord input

class Add
{
    public static void main (String[] args)
{
        int a,b,sum;
        a=Integer.parseInt(args[0]);
        b=Integer.parseInt(args[1]);
        sum=a+b;
        System.out.println("Sum: "+sum);
    }
}

5. Java program for Method Overloading

class Overload

{

            void area(int side)

            {

                        int ar;

                        ar=side*side;

                        System.out.println("Area of Square :"+ar);

            }

            void area(double radius)

            {

-                       double ar;

                       ar=3.14*radius*radius;

                        System.out.println("Area of Circle :"+ar);

            }

            void area(int length,int width)

            {

                        int ar;

                        ar=length*width;
                        System.out.println("Area of Rectangle:"+ar);

            }

}

class OverDemo

{

            public static void main(String args[ ])

            {

                        Overload ob=new Overload( );

                        ob.area(5);
                        ob.area(8,9);
                        ob.area(6.7);
            }

}

4. Input from keyboard

import java.util.*;

class nip

{

            public static void main(String ab[])

            {

                        Scanner sc=new Scanner(System.in);

                        int a,b,c;

                        System.out.println("a=");

                        a=sc.nextInt();

                        System.out.println("b=");

                        b=sc.nextInt();

                        c=a+b;

                        System.out.println("add="+c);

            }

}

3. Addition of two number using method

class Sample

{

            int a,b;

            void setAll(int i,int j)

            {

                        a=i;

                        b=j;

            }

            void showAll( )

            {

                        System.out.println("a= " + a + " b="+b);

            }

}

class SampleDemo

{

            public static void main(String args[ ])

            {

                        Sample ob=new Sample( );

                        ob.setAll(5,6);

                        ob.showAll( );

            }

}

2. Addition of two number

class Sum2

{

            public static void main(String args[ ])

            {

                        int a,b,c;

                        a=Integer.parseInt(args[0]);

                        b=Integer.parseInt(args[1]);

                        /*calculate the sum */

                        c=a+b;

                        System.out.println("Sum = "+c);

            }

}