your answer of the first question  is not clear to me.

say,i am trying to do..

class xyz{
....
try
{

//code block


}catch(ArithmeticException e)

{
System.out.println("arithmetic exception");
}

//blah

//blah

}


now say, code block  is throwing NullPointerException.....so it wont
be caught by the catch()....in this situation will the code  run??

you are talking about compilation errors....but i think it would be
runtime error...right?