pattern class is not a class of java.util.regex 

Which of these operators can be used to concatenate two or more string objects?

What is the main advantage of using BigDecimal over double?

class Demo{

 public static void main(string args[]){

  System.out.println(2+3);

 }

}

Which of the following classes is the superclass of FocusEvent?

Which event is generated when a computer gains or loses input focus?

class test{

public static void main (String[] args) {

  short s=150;

  byte b=(byte)s;

  System.out.println(b);

}

}

public class Abekus

{  

public static void main(String[] args) {

String str = "1234";

int a = Integer.parseInt(str);

System.out.println(a);

}

}

class A
{  
   protected int method1(int a, int b)
   {
       return 0;
   }
}


Which is valid in a class that extends class A?

Which option is correct to get the output as abekus.com?