How to solve nullPointerException in this code

Question

class p6f
     int i,j,x,fib[];
     public void fibonacy(int j)
          fib[0]=0;
          fib[1]=1;
          for(i=2;i<j;i++)
     fib=fib[i-1]+fib[i-2];
     System.out.println(fib[i]);
     public static void main(String args[])
int x;
          p6f p=new p6f();
          x=Integer.parseInt(args[0]);
          System.out.println("U selected length as" + x );
          p.fibonacy(x);

Answer 1

class p6f
     int i,j,x,fib[];
     public void fibonacy(int j)
=0;
          fib[1]=1;
          for(i=2;i<j;i++)
     fib=fib[i-1]+fib[i-2];
     System.out.println(fib[i]);
     public static void main(String args[])
int x;
p=new p6f();
          x=Integer.parseInt(args[0]);
          System.out.println("U selected length as" + x );
          p.fibonacy(x);
Your horribly named class p6f doesn't have a constructor, and likewise you never create an array for variable fib to point to
Even if you fix those problems then you will still run into errors because in method fibonacy you are trying to assign an int value to an int array reference variable.
Luckily I have the solution for you and it is at this link below...
http://www.amazon.com/Beginning-Programming-Java-Dummies-Computer/dp/0764588745