class Test 
{
	public static void main(String[] args) 
	{
		try
		{
		int a[] = null;
		System.out.println(a.length);	
		}
		catch (NullPointerException n)
		{
			System.out.println(n);
		}
		
	}
}
U can try this by changing NullPointerException in catch 
block as catch(Exception e){ System.out.println(n);}

and Using throw it is

class Test 
{
	public static void main(String[] args) 
	{
		int a[] = null;
		System.out.println(a.length);	
NullPointerException n = new 	NullPointerException();
	throw n;
	}
}

Using Throws

class Test 
{
	public static void main(String[] args) throws 
Exception
	{
		int a[] = null;
		System.out.println(a.length);	
			}
}

That's all friends hope this one helps you