java.lang

## Class NullPointerException

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

- All Implemented Interfaces:
    Serializable

      public class NullPointerException
      extends RuntimeException

  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.

  Since:
    JDK1.0
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `NullPointerException()` Constructs a `NullPointerException` with no detail message.
    `NullPointerException(String s)` Constructs a `NullPointerException` with the specified detail message.

  - ### Method Summary

    - ### Methods inherited from class java.lang.Throwable

      `addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, 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()

      Constructs a `NullPointerException` with no detail message.

    - #### NullPointerException

          public NullPointerException(String s)

      Constructs a `NullPointerException` with the specified detail message.
      Parameters:
        `s` - the detail message.

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