Thrown when an application attempts to use
null in a case where an object is required. These include:
- Calling the instance method of a
null object.
- Accessing or modifying the field of a
null object.
- Taking the length of
null as if it were an array.
- Accessing or modifying the slots of
null as if it were an array.
- Throwing
null as if it were a Throwable value.
Applications should throw instances of this class to indicate other illegal uses of the null object. NullPointerException objects may be constructed by the virtual machine as if suppression were disabled and/or the stack trace was not writable .