NullpointerException in Arrays.sort()

[amarkirt saroay]

   
import java.util.*;
public class Test {
 
   public static void main(String args[]){
 
   List<Integer> l=new ArrayList<Integer>();
   l.add(1);
   l.add(4);
   l.add(0);
   l.add(13);
   l.add(9);
   Object [] arr=l.toArray();
   Integer [] y=new Integer[10];
   y=l.toArray(y);
   Arrays.sort(y);//line 1
   for(int u:y)
   System.out.println(u);
   }
   
   } 
   
    

Why it gives runtime exception of Nullpointer in line 1?

[Srividhya Kiran]

Hi

When you create Integer[] y=new Integer[10];

By default, null values will be assigned to Integer Array Object 'y'.

Therefore sorting the array with null values returns in NullPointerException

Srividhya

[Ben Souther]

Hint:

Integer[] y = new Integer[l.size()];