Uninitialized Object vs Object Initialized to NULL

by

Correct, both static and instance members of reference type not explicitly initialized are set to null by Java. The same rule applies to array members.

From the Java Language Specification, section 4.12.5:

Initial Values of Variables

Every variable in a program must have a value before its value is used:

Each class variable, instance variable, or array component is initialized with a
default value when it is created

[…] For all reference types, the default value is null.

Note that the above rule excludes local variables: they must be initialized explicitly, otherwise the program will not compile.

More Related Contents:

  1. Initialization of an ArrayList in one line
  2. Method Overloading for null argument
  3. How to initialize an array in Java?
  4. Why are local variables not initialized in Java?
  5. Java: define terms initialization, declaration and assignment
  6. Should a retrieval method return ‘null’ or throw an exception when it can’t produce the return value? [closed]
  7. How come invoking a (static) method on a null reference doesn’t throw NullPointerException?
  8. When are static variables initialized?
  9. object==null or null==object?
  10. Null check chain vs catching NullPointerException
  11. Default values and initialization in Java
  12. Why can’t primitive data types be “null” in Java?
  13. Why does String.valueOf(null) throw a NullPointerException?
  14. Default constructors and inheritance in Java
  15. How to initialize HashSet values by construction?
  16. What is the point of the class Option[T]?
  17. Meaning of new Class(…){{…}} initialization idiom [duplicate]
  18. Java “?” Operator for checking null – What is it? (Not Ternary!)
  19. Which is more effective: if (null == variable) or if (variable == null)? [duplicate]
  20. Java method dispatch with null argument
  21. Comparable and Comparator contract with regards to null
  22. How to check a string against null in java?
  23. Why null cast a parameter? [duplicate]
  24. Uninitialized object leaked to another thread despite no code explicitly leaking it?
  25. Java Singleton Pattern
  26. Hibernate: How to set NULL query-parameter value with HQL?
  27. Java: how to initialize String[]?
  28. How to declare an ArrayList with values? [duplicate]
  29. Compilers behave differently with a null parameter of a generic method
  30. Initialize final variable before constructor in Java

Leave a Comment