Java

Variable Scope:

public class VarScopeProg
{
 public static void main(String[] args)
 {
   int A=10;
   {
     int B=20;
     System.out.println("Block A: "+A);
     System.out.println("Block B: "+B);
   }//scope of B=20 ends here
   {
   int B=30;//scope of B=30 starts here
   System.out.println("Block A: "+A);
   System.out.println("Block B: "+B);
   }//scope of B=30 ends here
   int B=40;//scope of B=40 starts here
   {
     System.out.println("Block A: "+A);
     System.out.println("Block B: "+B);

   }
 }//scope of all the variables end here
}

Use Of Class:

/*This is a Java program which shows the
use of class in the program
*/
class Rectangle
{
 int height;
 int width;
 void area()
 {
  int result=height*width;
  System.out.println(“The area is ”+result);
 }
}
class classDemo
{
 public static void main(String args[])
 {
  Rectangle obj=new Rectangle();
  obj.height=10;//setting the attribute values
  obj.width=20;//from outside of class
  obj.area();//using object method of class is called
 }
}

Type Casting

public class TypeCastProg

{

  public static void main(String[] args)

  {

     double x;

     int y;

     x=25.50;

     System.out.println("Value of [double] x: "+x);

     System.out.println("Conversion of double to integer");

     y=(int)x;

     System.out.println("Value of [integer] y: "+y);

     int m;

     double n;

     m=10;

     n=(double)m;

     System.out.println("Value of [integer] m: "+m);

     System.out.println("Conversion of integer to double");

     System.out.println("Value of [double] n: "+n);

  }

}

Exception Handling

class ExceptionDemo

{

 public static void main(String args[])

 {

   try

   { 

    int a,b;

    a=5;

    b=a/0;

   }

  catch(ArithmeticException e)

  {

   System.out.println("Divide by Zero\n");

  }

  System.out.println("...Executed catch statement");

 }

}

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