ap.java.lang
Class NullPointerException

java.lang.Object
  java.lang.Throwable
      java.lang.Exception
          java.lang.RuntimeException
              ap.java.lang.NullPointerException

All Implemented Interfaces:

java.io.Serializable

public class NullPointerException

extends java.lang.RuntimeException

Students should understand this error/exception when it occurs in a program.

An object of this class is thrown when a program attempts to use null when an object is required. For example:

• Calling a method of a null object.
• Accessing a field of a null object.
• Accessing null as if it were an array.

See Also:

Serialized Form

Constructor Summary

NullPointerException()

Methods inherited from class java.lang.Throwable

fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

NullPointerException

public NullPointerException()