Question

This question seems to be very basic, but I don’t know why, there is something wrong and I can’t figure it out.

int [] concept = null; 
int i = 0; 
for (Iterator iterator = conceptsListGeneral.iterator(); iterator.hasNext();) {  
    Map<String, Object> map = (Map<String, Object>) iterator.next();  
    String count = (String)map.get("count");  
//  concept[i] = new Integer(count).intValue();  
//  concept[i]= Integer.parseInt(count, 10);  
    Integer intObj2 = Integer.valueOf(count);  
    concept[i]= intObj2.intValue();  
    i++;
}

The comented lines are some of the thigs I have tried. I get a java.lang.NullPointerException on the last line.
By debugging, I know String count has a value, and olso Integer intObj2.
DOes anybody know why?? Thanks in advance

Answer 1

It’s just because your concept array is null. Replace your first line with

int[] concept = new int[conceptsListGeneral.size()] 

and you’ll have it working.

EDIT

Oh, and like Edwin says, don’t forget to assign i a value.