null pointer exception code example

Example 1: how to use a try catch for a null pointer exception in java

int n;//decalred as null
n = n + 1;//null pointer exception
/////////////////////////////////////
int n = 5;
n = n + 1;//no null pointer exception

Example 2: exception is null

//Bug with VS: Exception e == null
//Happens when multiple catch variables are the same
//an example of the solution:
try
{
    // do something
}
catch (WebException webEx) // using a variable named 'webEx' for this catch
{
    Logger.Log("Error while tried to do something. Error: " + webEx.Message); // <-
}
catch (Exception ex) // using a DIFFERENT variable for this one
{
    Logger.Log("Error while tried to do something. Error: " + ex.Message);
}

Example 3: null pointer exception

NullPointerExceptions are exceptions that occur when you try to 
use a reference that points to no location in memory (null)
 as though it were referencing an object.

Example 4: What’s null pointer exception?

First, null keyword it does not refers to any object at all. 
Null keyword means no object.
null pointer excep: there is no object at all.
So you can't get access to the instance of that object

Example 5: nullpointerexception java

Integer num;
num = new Integer(10);

Example 6: nullpointerexception java

int x;
x = 10;