NullPointerException
  public
  
  
  
  class
  NullPointerException
  
  
  
  
  
  
  
  
  
  
    extends RuntimeException
  
  
  
  
  
  
| java.lang.Object | ||||
| ↳ | java.lang.Throwable | |||
| ↳ | java.lang.Exception | |||
| ↳ | java.lang.RuntimeException | |||
| ↳ | java.lang.NullPointerException | |||
Thrown when an application attempts to use null in a
 case where an object is required. These include:
 
- Calling the instance method of a nullobject.
- Accessing or modifying the field of a nullobject.
- Taking the length of nullas if it were an array.
- Accessing or modifying the slots of nullas if it were an array.
- Throwing nullas if it were aThrowablevalue.
 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 stack trace was not writable.
Summary
| Public constructors | |
|---|---|
| 
      NullPointerException()
      Constructs a  | |
| 
      NullPointerException(String s)
      Constructs a  | |
| Inherited methods | |
|---|---|
Public constructors
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 | String: the detail message. | 
