Q1: What will be the output of the program?

public class NFE 
{
    public static void main(String [] args) 
    {
    String s = '42';
        try 
        {
            s = s.concat('.5');  /* Line 8 */
            double d = Double.parseDouble(s);
            s = Double.toString(d);
            int x = (int) Math.ceil(Double.valueOf(s).doubleValue());
            System.out.println(x);
        }
        catch (NumberFormatException e) 
        {
            System.out.println('bad number');
        }
    }
}

ANS:A - 42

All of this code is legal, and line 8 creates a new String with a value of '42.5'. Lines 9 and 10 convert the String to a double and then back again. Line 11 is fun— Math.ceil()'s argument expression is evaluated first. We invoke the valueOf() method that returns an anonymous Double object (with a value of 42.5). Then the doubleValue() method is called (invoked on the newly created Double object), and returns a double primitive (there and back again), with a value of (you guessed it) 42.5. The ceil() method converts this to 43.0, which is cast to an int and assigned to x.